Welcome to my world, AMD and Intel are very different, an optimizarion for intel can be a regression for AMD. And in each brand you have a lot of different GPU with their own issue.
CroqueMr , if it can help find the issue, I went back from beta5 to beta4 and the freeze when PGS subtitles + any GUI is on the screen at the same time4 was still there. Then I went back to Beta3 before the L5 fix with the cutted out GUI and the freeze is not there anymore. Maybe it has something to do with L5? Do you want a log of when it freezes?