In 1.9, skeletons were made so their arms would be like a player. If you have a skeleton with a sword, it's arms will go like 1.8 when attacking and will go back down rapidly without an animation, just the arms teleporting. It also attacks terribly
Related issues
duplicates
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I have noticed this too... But in 1.14! It was not an issue through 1.13, so perhaps it has come back to bite?
Confirmed for
15w36c
Duplicates MC-87093