To add more, I encountered this bug in Oct 2018 (brave-beta-bin-0.55.10-2), then I switched back to muon and It was displaying correcting in the old version.
I gave another try to the chromium based build recently and this bug persist.
So it should be lead by some old code before Oct last year. In case you’re trying to locate the bug.
This thread list all of the installed font on my system: Missing content in the Brave Shield