Ever since a few hours ago, Infection has been being very buggy. Such as players with iron armor can't be hit by zombies, and a lot of people are staying in the previous game instead of going to the lobby. I and I'm sure many other people hope that this will be fixed very soon.

 

It has been like that since it's re-release (not the iron armour issue). Im sure it will be fixed eventually. It might take some work.