Illagers in their patrols do not seem to be losing sight of the player consistently.

Expected behaviour would be that after a certain number of blocks they turn away and continue to do their own thing. Some of them do, yet some of them continue to stare even when I am quite a large number of blocks away.

I've run back and forth while staying at the same distance and they do in fact follow me with their gaze; it's not just coincidence that they are facing my directions (coincidences being like sometimes when a creeper "looks" at you through the window).

I've tested this by running to and fro, towards and away from them, as well as side to side to see if they are actually following me with their gaze. They're inconsistent in eventually turning away. Sometimes they'll turn around when I'm about twenty blocks away, but sometimes one will turn around and the others will continue to stare even when I'm about 30 blocks away.

I've also encountered an issue while being on a tower constructed of solid blocks, where they somehow followed me despite the fact that they should not have been able to see me (blocks should have been blocking their line of sight). I ran to one end of the tower in an attempt to jump off and escape, but they followed me there, even though it would have been impossible for them to see me until I was at the very edge because of the high walls.

I'm having these experiences with patrolling Illagers only. I have yet to trigger a raid, therefore I don't know if this behaviour persists in that situation. The village that these photos are taken in is empty (likely was wiped out by zombie sieges while I wasn't paying attention).