Radium/Canary breaks the animation (and Lithium as well probably, could not test it)

[iGuessImBlind]

Forge 1.20.1
If you equip 2 melee weapons in both hand and try attacking with both weapons the animation will break eventually, though you can reset it by attacking with 1 hand.

Fix:
set mixin.entity.fast_hand_swing to false in Canary configuration file