Freezing in battle.

Did anyone come across the problem of freeze the character in battle? He loses the border of fast running. The grenade simply hangs in his hand and he does not throw it. If you choose a weapon (main or secondary), it simply shoots without stopping. After some time, everything stops and the game continues normally, but then it may be repeated again. This happens only in multiplayer and a Portal, in the single mode there are no such problems. PC platform.
Thx.