Usually when a mob gets angry like a zombie piglin, wolf, or any that broadcasts their anger "minecraft:angry" apparently, they "should" be calm after that. This bug isn't the case.

The bug i discovered doesn't cooperate with it. When a wolf is targeting a sheep, however, a sheep is already killed by another mob or player, they remain as angry and won't attack another sheep until the anger timer is done. 

This happens in both creative and/or survival

Wolf is one of the examples in the clip