Cancelling the endlag of a charged shot causes the next attack/attempt to go into Aim mode to immediately cancel. The bugged state persists for at least 30+ seconds if you don't attack, and throwing baron bunny/oz doesn't fix it either. Switching characters or teleporting does, though.
There's another bug that triggers at 0:14, where the UI screws up and shows my bindings as incorrect, that's why I accidentally switched to Jean when I inputted Up to switch to Venti as the UI said should happen.