Warzone couldn't swap weapons.

So I was playing warzone, which was pretty fun I must say, and along woth the terrible lag I was experiencing, not just in warzone but every other game type i tried, I could not change any of my weapons. I know you have to wait till your req level goes up, and I did, but it still wasn’t swapping. I’m not sure if it was the lag or what, but it was very frustrating.