That’s me. (The names you see are different).
I simply removed Microsoft YaHei Light.
Hopefully my modifications will be incorporated into the defaults.
The help site has been fixed, but other users’ Publish sites remain unmodified. Do all Japanese Obsidian users have to customize their Publish CSS?
Also, I have not completely resolved the issue with the help site.
As for Interactive Graph, it still has the wrong font.
Related: Graph view should follow global "interface font"
I hope to eliminate Microsoft YaHei Light from Obsidian.