Thanks for the quick answer. This fixed the Plex subtitle size, but this again affects other applications e.g. apple tv’s own content and the sub. size gets too small. So there is no way to adjust the sub. size inside the Plex app at this time? (Like it was before and like it is on android, web player etc.)
For Direct plays it always uses the system subtitle settings. The old app setting only controlled subtitles transcoded by the server which we removed so they are consistent transcoded or not.