`range` option not working properly in `setmathfont`

I want to use XITS Math font for numbers and Latin Modern Math by default. But

documentclass{article}
usepackage{unicode-math}
setmathfont{Latin Modern Math}
setmathfont{XITS Math}[range={`0-`9}]

begin{document}
1234567890
$ x^{2}+y^{2}=z^{2}, xialphabeta, 1234567890 $
end{document}

produces

A magic number "0391 helps to generate the intended output

documentclass{article}
usepackage{unicode-math}
setmathfont{Latin Modern Math}
setmathfont{XITS Math}[range={`0-`9,"0391}]

begin{document}
1234567890
$ x^{2}+y^{2}=z^{2}, xialphabeta, 1234567890 $
end{document}

All effective numbers are "0391-"03A1,"03A3-"03AF,"03B1-"03BF,"03F4,"2202,"2207,"1D434-"1D454,"1D456-"1D467,"1D6E2-"1D6FA,"1D6FC-"1D714.

Why are these numbers so special?

documentclass{article}
usepackage{unicode-math}
setmathfont{Latin Modern Math}
setmathfont{XITS Math}[range={up/num,
                               bfup/num},
                        Scale=MatchUppercase]

begin{document}
1234567890
$ x^{2}+y^{2}=z^{2}, xialphabeta, 1234567890 $
end{document}