Staggering from non-crush through weapons

[Maroon]

Did You have any support item equipped?
If You have any med kits or any barricades in Your hand, this will happen.
If You just had a shield with a 1h melee weapon or just a shield, could it have been Your ping or did You have lags?

Actually, it happens if you're holding any throwing weapon in throwing mode in your hand while holding your shield up. Since support items count as throwing weapons, it also happens with them. To counter it, either grab a one hander instead of what you were using, or, in the case of throwing weapons, switch them to melee mode.