"Unable to connect to world. The world is no longer available to join"

Trying to get into my gf's world, I'm always stopped by the error saying "Unable to connect. World not available to join". 

We tried both restarting our routers and consoles 

We also tried getting into another friend's world without success

We unfriended each other and added again to see if it helped

Nothing works.

 

Please, fix this asap. We never had problems last patch, but couldn't play together for days now, ever since the new patch was released.