The frame rate doesn't go very low (for my pc 30fps is of normal condition). It's also true for singleplayer so it's probably not caused by lagging.
MC-134122
Graphic gliches slightly when rotating camera while walking
Resolved
Awaiting Response
0
Please check if that's still an issue for you in the latest 1.14.4 stable release or the latest 1.15 development snapshot.