I am having the same problem.
Cannot join the lobby unless it is Via a VPN. until recently it actually had worked without VPN, so it is very strange, and i didn't change anythin, just woke up today and it's stopped working. I am in vietnam at the min.
Seen this asked many times on here but doesn't seem to have an answer in the threads, something to do with the IP i think, if there is a solution it would be greatly appreciated