Same issue here, I have reinstalled multiple times on separate drives, reinstalled sound, and video drives even switched out my keyboard and mouse. The symptoms are still exactly the same every game.
Symptoms
1. First entering the game lobby significant choppiness for about 10 seconds and then everything is fine.
2. Banners for team selection come across and sound/game become choppy for 3 seconds
3. Through the game switching weapons, ring sound closure, landing all cause weird input lag symbol to pop up
4. Exiting the game has significant stutters and lag all the way through back to the lobby clicking continue after 2-3 seconds all is well until the next game.
Not sure what else to try at this point hoping the next update reset something as I do not think its my PC anymore.