I just noticed that my Beelink GT King has some problems in correctly playing movies when srt subtitles are active. I started to notice this when I updated to the CE-Matrix. I then returned to CE 9.2.x but I still see the stutter (while I didn’t see it previously with the same Coreelec versions).
I used to have the same video stutter quite a while ago when using LibreElec (don’t remember if it was on this GT King or the old Beelink GT): i managed to correct it by using the dirtyregion option in advancedsettings. I tried it on coreelec but no improvement.
I uploaded a minute or so of the movie for better explaining what I mean: you can notice the stutter on minute 0:04, 1:00, 1:07.