Hostile Endermen, that have been turned hostile by other means than looking at their face will turn Neutral again when looked at.
How to reproduce:
Punch an Enderman in survival mode, and then look at their face.
The Enderman stops attacking the player as long as the player is looking at their face.
When the player stops looking at their face the enderman starts attacking again.
I think Henrik fixed the original bug. The behavior when looking at their face is different from 20w22 when compared to 1.16-pre2.
It has instead been replaced with a worse version of MC-159757 where Enderman are now even unable to teleport when looked at, making them completely defenseless to the player as long as you look at them.