The Bug:
The facing directions of sniffers don't always match their visual facing rotation.
Steps to Reproduce:
Summon a sniffer.
Enable entity hitboxes by pressing "F3 + B".
Stand adjacent to the sniffer so that it eventually looks in your direction.
Take note as to whether or not the facing directions of sniffers don't always match their visual facing rotation.
Observed Behavior:
The facing directions of sniffers don't always match their visual facing rotation.
Expected Behavior:
The facing directions of sniffers would match their visual facing rotation.
This issue was fixed in 1.19.4 Pre-release 1. The fixing of MC-260109 in 1.19.4 Pre-release 1 allowed sniffers to rotate their heads with their eye line, which ultimately fixed this problem.