Might not have priority over LMB and RMB 
I have the same issue with a lot of classes when trying to quick swap from ranged to melee… this was a problem a while ago aswell but I bet the changes listed above reverted it to the worse.
Same happens when trying to swap weapons with Krubers spear and shield while performing 2nd light attack… can’t even block cancel the attack at the very start when the spear is still out of screen at the lower left corner… might be off-topic since I don’t know if its the same origin of the problem.