Android TV app not displaying any subtitles containing italicised text

Edit: Clarified that only lines with italicised text are affected
Server Version#: 1.43.0.10162
Player Version#: 10.30.6.4151

When I direct play media with ASS subtitles on my Android TV (Sony Bravia OLED), some subtitles are consistently missing. This seems to affect all lines that include any amount of italicised text. Forcing burning in all subtitles works around the issue, but transcoding everything isn’t great.

This started after a Android TV app this year and seems to affect all of my media tested so far (all use ASS subs, no complex effects), which displayed subtitles correctly before. First noticed while running server version 1.42.2, updating to 1.43.0 has not changed anything.

(Also a separate, long-running bug on this Sony TV is that the local subtitles are consistently rendered much darker than they should be, with white text being grey and other colours not matching the video. This is not a new bug and has been occurring since I first installed Plex on this TV a few years ago).