Fandol fonts does not contain requested, but I have already install it

I used Ubuntu 18.04 in WSL2.

Editor is Vscode 1.44.0, with plugin LaTeX Workshop 8.8.0

TeX Distributions is Texlive 2020

My .tex file is like this

documentclass[a4paper, 12pt]{book}
title{一个标题}
author{syc}
usepackage{xeCJK}
begin{document}
maketitle
newpage

hello, world

你好，世界

end{document}

The log file I’ve got

This is XeTeX, Version 3.14159265-2.6-0.999992 (TeX Live 2020) (preloaded format=xelatex 2020.4.13)  14 APR 2020 08:51
entering extended mode
 restricted write18 enabled.
 file:line:error style messages enabled.
 %&-line parsing enabled.
**/mnt/c/Users/songy/Desktop/tample/HBUThesis/test
(/mnt/c/Users/songy/Desktop/tample/HBUThesis/test.tex
LaTeX2e <2020-02-02> patch level 5
L3 programming layer <2020-04-06> (/home/syc/texlive/2020/texmf-dist/tex/latex/base/book.cls
Document Class: book 2019/12/20 v1.4l Standard LaTeX document class
(/home/syc/texlive/2020/texmf-dist/tex/latex/base/bk12.clo
File: bk12.clo 2019/12/20 v1.4l Standard LaTeX file (size option)
)
c@part=count163
c@chapter=count164
c@section=count165
c@subsection=count166
c@subsubsection=count167
c@paragraph=count168
c@subparagraph=count169
c@figure=count170
c@table=count171
abovecaptionskip=skip47
belowcaptionskip=skip48
bibindent=dimen134
) (/home/syc/texlive/2020/texmf-dist/tex/xelatex/xecjk/xeCJK.sty (/home/syc/texlive/2020/texmf-dist/tex/latex/l3kernel/expl3.sty
Package: expl3 2020-04-06 L3 programming layer (loader) 
 (/home/syc/texlive/2020/texmf-dist/tex/latex/l3backend/l3backend-xdvipdfmx.def
File: l3backend-xdvipdfmx.def 2020-03-12 L3 backend support: xdvipdfmx
g__graphics_track_int=count172
l__pdf_internal_box=box45
g__pdf_backend_object_int=count173
g__pdf_backend_annotation_int=count174
))
Package: xeCJK 2020/02/18 v3.8.2 Typesetting CJK scripts with XeLaTeX
 (/home/syc/texlive/2020/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
Package: l3keys2e 2020-03-06 LaTeX2e option processing using LaTeX3 keys
) (/home/syc/texlive/2020/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
Package: xtemplate 2020-03-06 L3 Experimental prototype document functions
l__xtemplate_tmp_dim=dimen135
l__xtemplate_tmp_int=count175
l__xtemplate_tmp_muskip=muskip16
l__xtemplate_tmp_skip=skip49
) (/home/syc/texlive/2020/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
Package: xparse 2020-03-06 L3 Experimental document command parser
l__xparse_current_arg_int=count176
g__xparse_grabber_int=count177
l__xparse_m_args_int=count178
l__xparse_v_nesting_int=count179
)
l__xeCJK_tmp_int=count180
l__xeCJK_tmp_box=box46
l__xeCJK_tmp_dim=dimen136
l__xeCJK_tmp_skip=skip50
g__xeCJK_space_factor_int=count181
l__xeCJK_begin_int=count182
l__xeCJK_end_int=count183
c__xeCJK_CJK_class_int=XeTeXcharclass1
c__xeCJK_FullLeft_class_int=XeTeXcharclass2
c__xeCJK_FullRight_class_int=XeTeXcharclass3
c__xeCJK_HalfLeft_class_int=XeTeXcharclass4
c__xeCJK_HalfRight_class_int=XeTeXcharclass5
c__xeCJK_NormalSpace_class_int=XeTeXcharclass6
c__xeCJK_CM_class_int=XeTeXcharclass7
c__xeCJK_HangulJamo_class_int=XeTeXcharclass8
l__xeCJK_last_skip=skip51
g__xeCJK_node_int=count184
c__xeCJK_CJK_node_dim=dimen137
c__xeCJK_CJK-space_node_dim=dimen138
c__xeCJK_default_node_dim=dimen139
c__xeCJK_default-space_node_dim=dimen140
c__xeCJK_CJK-widow_node_dim=dimen141
c__xeCJK_normalspace_node_dim=dimen142
l__xeCJK_ccglue_skip=skip52
l__xeCJK_ecglue_skip=skip53
l__xeCJK_punct_kern_skip=skip54
l__xeCJK_last_penalty_int=count185
l__xeCJK_last_bound_dim=dimen143
l__xeCJK_last_kern_dim=dimen144
l__xeCJK_widow_penalty_int=count186

Package xtemplate Info: Declaring object type 'xeCJK/punctuation' taking 0
(xtemplate)             argument(s) on line 2302.

l__xeCJK_fixed_punct_width_dim=dimen145
l__xeCJK_mixed_punct_width_dim=dimen146
l__xeCJK_middle_punct_width_dim=dimen147
l__xeCJK_fixed_margin_width_dim=dimen148
l__xeCJK_mixed_margin_width_dim=dimen149
l__xeCJK_middle_margin_width_dim=dimen150
l__xeCJK_bound_punct_width_dim=dimen151
l__xeCJK_bound_margin_width_dim=dimen152
l__xeCJK_margin_minimum_dim=dimen153
l__xeCJK_kerning_total_width_dim=dimen154
l__xeCJK_same_align_margin_dim=dimen155
l__xeCJK_different_align_margin_dim=dimen156
l__xeCJK_kerning_margin_width_dim=dimen157
l__xeCJK_kerning_margin_minimum_dim=dimen158
l__xeCJK_bound_dim=dimen159
l__xeCJK_reverse_bound_dim=dimen160
l__xeCJK_margin_dim=dimen161
l__xeCJK_minimum_bound_dim=dimen162
l__xeCJK_kerning_margin_dim=dimen163
g__xeCJK_family_int=count187
l__xeCJK_fam_int=count188
g__xeCJK_fam_allocation_int=count189
l__xeCJK_verb_case_int=count190
l__xeCJK_verb_exspace_skip=skip55
 (/home/syc/texlive/2020/texmf-dist/tex/latex/fontspec/fontspec.sty
Package: fontspec 2020/02/21 v2.7i Font selection for XeLaTeX and LuaLaTeX
 (/home/syc/texlive/2020/texmf-dist/tex/latex/fontspec/fontspec-xetex.sty
Package: fontspec-xetex 2020/02/21 v2.7i Font selection for XeLaTeX and LuaLaTeX
l__fontspec_script_int=count191
l__fontspec_language_int=count192
l__fontspec_strnum_int=count193
l__fontspec_tmp_int=count194
l__fontspec_tmpa_int=count195
l__fontspec_tmpb_int=count196
l__fontspec_tmpc_int=count197
l__fontspec_em_int=count198
l__fontspec_emdef_int=count199
l__fontspec_strong_int=count266
l__fontspec_strongdef_int=count267
l__fontspec_tmpa_dim=dimen164
l__fontspec_tmpb_dim=dimen165
l__fontspec_tmpc_dim=dimen166
 (/home/syc/texlive/2020/texmf-dist/tex/latex/base/fontenc.sty
Package: fontenc 2020/02/11 v2.0o Standard LaTeX package
) (/home/syc/texlive/2020/texmf-dist/tex/latex/fontspec/fontspec.cfg))) (/home/syc/texlive/2020/texmf-dist/tex/xelatex/xecjk/xeCJK.cfg
File: xeCJK.cfg 2020/02/18 v3.8.2 Configuration file for xeCJK package
))

Package xeCJK Warning: Fandol is being set as the default font for CJK text.
(xeCJK)                Please make sure it has been properly installed.


Package fontspec Warning: Font "FandolSong-Regular" does not contain requested
(fontspec)                Script "CJK".


Package fontspec Info: Font family 'FandolSong-Regular(0)' created for font
(fontspec)             'FandolSong-Regular' with options
(fontspec)             [Script={CJK},Extension={.otf},BoldFont={FandolSong-Bold},ItalicFont={FandolKai-Regular}].
(fontspec)              
(fontspec)              This font family consists of the following NFSS
(fontspec)             series/shapes:
(fontspec)              
(fontspec)             - 'normal' (m/n) with NFSS spec.:
(fontspec)             <->"[FandolSong-Regular.otf]/OT:language=dflt;"
(fontspec)             - 'small caps'  (m/sc) with NFSS spec.: 
(fontspec)             - 'bold' (b/n) with NFSS spec.:
(fontspec)             <->"[FandolSong-Bold.otf]/OT:language=dflt;"
(fontspec)             - 'bold small caps'  (b/sc) with NFSS spec.: 
(fontspec)             - 'italic' (m/it) with NFSS spec.:
(fontspec)             <->"[FandolKai-Regular.otf]/OT:language=dflt;"
(fontspec)             - 'italic small caps'  (m/scit) with NFSS spec.: 

(./test.aux)
openout1 = `test.aux'.

LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for TS1/cmr/m/n on input line 5.
LaTeX Font Info:    Trying to load font information for TS1+cmr on input line 5.
 (/home/syc/texlive/2020/texmf-dist/tex/latex/base/ts1cmr.fd
File: ts1cmr.fd 2019/12/16 v2.5j Standard LaTeX font definitions
)
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for TU/lmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 5.
LaTeX Font Info:    ... okay on input line 5.

Package fontspec Info: Adjusting the maths setup (use [no-math] to avoid
(fontspec)             this).

symlegacymaths=mathgroup4
LaTeX Font Info:    Overwriting symbol font `legacymaths' in version `bold'
(Font)                  OT1/cmr/m/n --> OT1/cmr/bx/n on input line 5.
LaTeX Font Info:    Redeclaring math accent acute on input line 5.
LaTeX Font Info:    Redeclaring math accent grave on input line 5.
LaTeX Font Info:    Redeclaring math accent ddot on input line 5.
LaTeX Font Info:    Redeclaring math accent tilde on input line 5.
LaTeX Font Info:    Redeclaring math accent bar on input line 5.
LaTeX Font Info:    Redeclaring math accent breve on input line 5.
LaTeX Font Info:    Redeclaring math accent check on input line 5.
LaTeX Font Info:    Redeclaring math accent hat on input line 5.
LaTeX Font Info:    Redeclaring math accent dot on input line 5.
LaTeX Font Info:    Redeclaring math accent mathring on input line 5.
LaTeX Font Info:    Redeclaring math symbol colon on input line 5.
LaTeX Font Info:    Redeclaring math symbol Gamma on input line 5.
LaTeX Font Info:    Redeclaring math symbol Delta on input line 5.
LaTeX Font Info:    Redeclaring math symbol Theta on input line 5.
LaTeX Font Info:    Redeclaring math symbol Lambda on input line 5.
LaTeX Font Info:    Redeclaring math symbol Xi on input line 5.
LaTeX Font Info:    Redeclaring math symbol Pi on input line 5.
LaTeX Font Info:    Redeclaring math symbol Sigma on input line 5.
LaTeX Font Info:    Redeclaring math symbol Upsilon on input line 5.
LaTeX Font Info:    Redeclaring math symbol Phi on input line 5.
LaTeX Font Info:    Redeclaring math symbol Psi on input line 5.
LaTeX Font Info:    Redeclaring math symbol Omega on input line 5.
LaTeX Font Info:    Redeclaring math symbol mathdollar on input line 5.
LaTeX Font Info:    Redeclaring symbol font `operators' on input line 5.
LaTeX Font Info:    Encoding `OT1' has changed to `TU' for symbol font
(Font)              `operators' in the math version `normal' on input line 5.
LaTeX Font Info:    Overwriting symbol font `operators' in version `normal'
(Font)                  OT1/cmr/m/n --> TU/lmr/m/n on input line 5.
LaTeX Font Info:    Encoding `OT1' has changed to `TU' for symbol font
(Font)              `operators' in the math version `bold' on input line 5.
LaTeX Font Info:    Overwriting symbol font `operators' in version `bold'
(Font)                  OT1/cmr/bx/n --> TU/lmr/m/n on input line 5.
LaTeX Font Info:    Overwriting symbol font `operators' in version `normal'
(Font)                  TU/lmr/m/n --> TU/lmr/m/n on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathit' in version `normal'
(Font)                  OT1/cmr/m/it --> TU/lmr/m/it on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathbf' in version `normal'
(Font)                  OT1/cmr/bx/n --> TU/lmr/b/n on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathsf' in version `normal'
(Font)                  OT1/cmss/m/n --> TU/lmss/m/n on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathtt' in version `normal'
(Font)                  OT1/cmtt/m/n --> TU/lmtt/m/n on input line 5.
LaTeX Font Info:    Overwriting symbol font `operators' in version `bold'
(Font)                  TU/lmr/m/n --> TU/lmr/b/n on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathit' in version `bold'
(Font)                  OT1/cmr/bx/it --> TU/lmr/b/it on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathsf' in version `bold'
(Font)                  OT1/cmss/bx/n --> TU/lmss/b/n on input line 5.
LaTeX Font Info:    Overwriting math alphabet `mathtt' in version `bold'
(Font)                  OT1/cmtt/m/n --> TU/lmtt/b/n on input line 5.
LaTeX Font Info:    External font `cmex10' loaded for size
(Font)              <14.4> on input line 6.
LaTeX Font Info:    External font `cmex10' loaded for size
(Font)              <7> on input line 6.
 [1


] [2] (./test.aux) ) 
Here is how much of TeX's memory you used:
 4571 strings out of 481357
 143488 string characters out of 5927161
 433007 words of memory out of 5000000
 21989 multiletter control sequences out of 15000+600000
 533363 words of font info for 41 fonts, out of 8000000 for 9000
 36 hyphenation exceptions out of 8191
 46i,6n,73p,326b,241s stack positions out of 5000i,500n,10000p,200000b,80000s

Output written on test.pdf (2 pages).

And I already installed fandol fonts

~/texlive/2020/texmf-dist/fonts/opentype/public/fandol
❯ la
total 34M
-rw-r--r-- 1 syc syc  26K Jul 19  2015 FandolBraille-Display.otf
-rw-r--r-- 1 syc syc  13K Jul 19  2015 FandolBraille-Regular.otf
-rw-r--r-- 1 syc syc 6.7M Jul 19  2015 FandolFang-Regular.otf
-rw-r--r-- 1 syc syc 3.5M Jul 19  2015 FandolHei-Bold.otf
-rw-r--r-- 1 syc syc 5.6M Jul 19  2015 FandolHei-Regular.otf
-rw-r--r-- 1 syc syc 7.5M Jul 19  2015 FandolKai-Regular.otf
-rw-r--r-- 1 syc syc 5.6M Jul 19  2015 FandolSong-Bold.otf
-rw-r--r-- 1 syc syc 4.8M Jul 19  2015 FandolSong-Regular.otf

Even I put them in the font floders

❯ fc-list | grep fandol
/usr/share/fonts/fandol/FandolFang-Regular.otf: FandolFang,FandolFang R:style=Regular
/usr/share/fonts/fandol/FandolBraille-Display.otf: Fandol Braille,Fandol Braille Display:style=Display,Regular
/usr/share/fonts/fandol/FandolBraille-Regular.otf: Fandol Braille,Fandol Braille Regular:style=Regular
/usr/share/fonts/fandol/FandolSong-Bold.otf: FandolSong:style=Bold
/usr/share/fonts/fandol/FandolKai-Regular.otf: FandolKai:style=Regular
/usr/share/fonts/fandol/FandolHei-Bold.otf: FandolHei:style=Bold
/usr/share/fonts/fandol/FandolSong-Regular.otf: FandolSong:style=Regular
/usr/share/fonts/fandol/FandolHei-Regular.otf: FandolHei:style=Regular

How to solve these Warning?