I'm pretty new at Libreelec but a Kodi (XBMC) veteran on other playforms since the old XBMC days (primary OSX/Mac Mini).
I installed the latest LE 9.2.1 on my RPI4 (4GB model, not overclocked) and everything seems to run pretty well, at least af first glance). But I have noticed that video playback (1080p video and 1080p HDMI output) is slightly uneven/juddery (micro-stutter?) - for lack of better description. This is consistant behaviour when playing the same video files, and happens streaming over both wifi and wired LAN. I have also tried to increase cache size via advancedsettings, This makes no difference to smoothness of playback. I have also tried "Adjust display refresh rate to match video" and "Sync playback to display" options which do help, but only slightly.
I have compared playback of the exact same files to my Kodi old setup (Mac Mini with old Kodi version) - video files plays perfectly on the old setup, no "micro-stuttering".
My question is: is this normal behaviour for LE/Kodi on RPI4 (not optimized video driver?) or something I can fix?
Any constructive advice is welcome - thank you 
/T