[Gameplay] Champions do not automatically attack minions after 4.20

I was playing a few games as Vi and I noticed that, while clearing minion waves with her Q and E combo, she would not automatically (a.k.a without being given an attack command or an attack-move command) attack/continue attacking the enemy creeps adjacent to her. Usually I would be able to clear the minion waves and let her continue attacking the minions while directing my attention elsewhere, and she would automatically attack the next closest minion after killing one, on her own. After the patch, Vi just stands prone after she kills the minion she is currently attacking, even in the middle of a big creep wave.

Tested and confirmed this with other champions (Diana, Leona, Ashe) as well - none of them would move to attack the next closest minion either.

I hope this makes sense? I can take a video of the above happening later on.