Most frustrating to me are:
Rein ult on breakable floor damages and destroys the floor without damaging or stunning enemies on top of it.
I’d post a clip of this, but it won’t let me post a link.
Two short stairways have a top step that acts as a wall when rein charging or punching with doomfist instead of letting you charge through the doorway.
There are various other sloped areas that have weird interactions with certain abilities, but these are the most notable and they happen 100% of the time.