Infinite loading screen when joining others

[tiny ember]

When I try to join my brother via invite code I get stuck on a loading screen for ages, same thing happens when I attempt to host my own so he can join. He is not experiencing this problem. Internet connection is fine, everything else runs smoothly. Single player runs smoothly its only when I try to host or join others I get this problem. I have already completed all the steps on the FAQ to try and fix this