Tahm's Devour prioritize minions after 5.18 in messy fights [GAMEPLAY]

I am not sure is that game mechanics bug or just me, but after 5.18 i tested Tahm and It became smoothy and his casts appears to be more responsive. At the same time, fast reactive casts (especially noticeable on smartcast) behave very strange in messy teamfights when monsters and creeps are involved. It seems that system reacts badly on new "smoothness".

I noticed the repeatable failes in priority when you try use Devour fast in very close teamfights, especially with lane creeps involved.

Priority favours creeps when u target devour on champions if creep somehow crosses the champion model. This happens mostly with lane creeps, when fight happens around monsters cursor tends to choose right (closest target), but when champion like Fizz (ignores collision) or after some gap closing skills (Jax q or Alistar's W) if champion somehow covers creep model Devour somehow chooses minion in most cases.
Yes, i know about missplays, but i tested it also with AI and it happens to be true. In very many (more than 60%) targeting moves to lesser size target if models lay on each other (2 ally champions and creep inside target ring).