https://bugs.winehq.org/show_bug.cgi?id=55142
--- Comment #14 from Zeb Figura z.figura12@gmail.com --- (In reply to Zeb Figura from comment #13)
(In reply to Zeb Figura from comment #12)
????????????
Ah, so it probably doesn't support characters outside of the BMP correctly... that was an attempt to type Linear B, which clearly failed.
Looks like it's probably fixed in more recent Bugzilla:
https://bugzilla.mozilla.org/show_bug.cgi?id=1253535#c78