Koma-Script scrartcl.cls + newfile.sty: readstream stops after section+newline in file

I am using newfile.sty to generate a file, which I then read again. With Koma-Script it stopped working since TeXLive 2020: If the file contains a newline after a sectioning command like chapter or section, readstream stops reading the stream after the newline character:

Minium example:

documentclass{scrartcl}
usepackage{newfile}
begin{document}
section{Eins}
Writing into a file here:

newoutputstream{lsg}
openoutputfile{min.lsg}{lsg}
addtostream{lsg}{This is before the section protectsection{Zwei} and this is after it.}
addtostream{lsg}{This is  after a newline in the file.}
closeoutputstream{lsg}

Reading from file stops at the first newline character that appears after the
sectioning command:

newinputstream{lsg}%
openinputfile{min.lsg}{lsg}%
readstream{lsg}

end{document}

With the standard article.cls it works as expected:

documentclass{article}
usepackage{newfile}
begin{document}
section{Eins}
Writing into a file here:

newoutputstream{lsg}
openoutputfile{min.lsg}{lsg}
addtostream{lsg}{This is before the section protectsection{Zwei} and this is after it.}
addtostream{lsg}{This is  after a newline in the file.}
closeoutputstream{lsg}

Reading from file stops at the first newline character that appears after the
sectioning command:

newinputstream{lsg}%
openinputfile{min.lsg}{lsg}%
readstream{lsg}

end{document}

Log-File

This is LuaHBTeX, Version 1.12.0 (TeX Live 2020)  (format=lualatex 2020.5.18)  21 JUN 2020 13:17
 system commands enabled.
 file:line:error style messages enabled.
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(./min.tex
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. L3 programming layer <2020-03-06>
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LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 4.
LaTeX Font Info:    ... okay on input line 4.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 4.
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LaTeX Font Info:    Checking defaults for TS1/cmr/m/n on input line 4.
LaTeX Font Info:    Trying to load font information for TS1+cmr on input line 4.

 (/usr/local/texlive/2020/texmf-dist/tex/latex/base/ts1cmr.fd
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LaTeX Font Info:    ... okay on input line 4.
LaTeX Font Info:    Checking defaults for TU/lmr/m/n on input line 4.
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LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 4.
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LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 4.
LaTeX Font Info:    ... okay on input line 4.
Package scrbase Info: activating english contentsname on input line 4.
Package scrbase Info: activating english listfigurename on input line 4.
Package scrbase Info: activating english listtablename on input line 4.
lsgoutstre@m=write3

openout3 = min.lsg
lsginstre@m=read3

[1

{/usr/local/texlive/2020/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
(./min.aux))

Here is how much of LuaTeX's memory you used:
 3053 strings out of 480992
 100000,552014 words of node,token memory allocated
 426 words of node memory still in use:
   3 hlist, 1 vlist, 1 rule, 2 glue, 3 kern, 1 glyph, 4 attribute, 52 glue_spec,
 4 attribute_list, 1 write nodes
   avail lists: 2:51,3:14,4:2,5:30,6:5,7:211,9:18,10:1,11:12
 20563 multiletter control sequences out of 65536+600000
 28 fonts using 3653771 bytes
 42i,6n,54p,10121b,248s stack positions out of 5000i,500n,10000p,200000b,100000s
</usr/local/texlive/2020/texmf-dist/fonts/opentype/public/lm/lmroman10-regular.o
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f>
Output written on min.pdf (1 page, 7613 bytes).

PDF statistics: 22 PDF objects out of 1000 (max. 8388607)
 12 compressed objects within 1 object stream
 0 named destinations out of 1000 (max. 131072)
 1 words of extra memory for PDF output out of 10000 (max. 100000000)