Since the start of the 1.14 snapshots, i've noticed that when using my server, my player's rotation keeps jumping around (see video attached).
There are no logs on the server side indicating that the server could not keep up, nor is my ping of any concern (2ms to the server and back).
The clip reordered is from the nether on 19w13b, however I have been noticing this ever since the first 1.14 snapshots (1.13.2 and below is fine).
Server specs (if useful):
8GB RAM (server.jar allocated 4GB)
i5-2310m - 2C/4T @2.2GHZ
Max of 2-3 players at any time.