I wasn't able to play with friends since Saturday. When trying to join them it always says "Can't connect to server" and when they try to join my world they get the same error message.

We tried to play together on Saturday, Sunday and Monday, so we couldn't play for the last 3 days, always getting the same error message.

We restarted consoles and PCs, and even reinstalled the game. Anything worked.

I can play alone in one of my worlds, and I can join the featured public Servers, maybe this information helps.