Ammo Crates and other bits.

[ispellcorrectly]

Crouching/Standing next to ammo crates for a refill and then trying to run directly forward…

You get ‘stuck’.

When switching weapons sometimes, you cannot shoot straight away, mostly as a sniper.

Sometimes, when going for a full revive as medic, the defibs stay out and does not return to weapon which was selected.

[AssortedStuff]

…and being killed while standing on an ammo crate would make you sink through the crate, you’d be incapacitated inside the crate.
Not sure if it has been fixed with the last patch.