I've seen quite a few people have been dealing with the same issue (along with others that've came from the May update. Hopefully the June one will resolve this (and the other) issues that A32 5G owners have been experiencing.
You also could try uninstalling the current version of YouTube and see if it helps any. I experienced the same thing with streaming in general and found that it was just the area I was in was responsible. Even though it didn't happen until after the Upgrade.