[thx9000]

I've been having the same problem for awhile. In the beginning I thought it was kodi having trouble with some file types but eventually narrowed it down to the subtitles.
I tried messing with algorithmdirtyregions, nofliptimeout and smartredraw in advancedsettings but none of the combinations got rid of the stutter. I was able to achieve smoother and more responsive interface at best.
Kodi 18.4 on Sony Android TV 8.0