Steps to Reproduce:

1. Use the following command:

   /effect give @s minecraft:haste infinite 4
   

2. Try to punch, break of place something and observe.

Observed Results:
Haste levels larger than 3 will prevent the arm swing animation from playing. The arm just goes down similar to the item swap animation, which gets increasingly more subtle with higher levels, until it stops completely at level 39.

Expected Results:
The arm swing animation plays regardless of level.