I can't join my friends anywhere but on servers like The Hive since many months, and I can't find the problem.

When I try to join their worlds, my screen shows the "unable to connect to world" error; when they try to join my world, it does it for them too, telling that it might be a network problem. Multiplayer was activated for our worlds, we've tried disconnecting from our Microsoft accounts and reconnecting to them, we've tried switching off and on our devices and it still didn't work. I've tried it with friends next to me while they had the same device I have (Nintendo Switch) and I've tried with friends who were far away and had a different device. We had the same version of the game and tried it after several updates. It only affects me as my friends can play with other friends of them.

As I was saying, the strangest part about this is that we can still join each others in servers like The Hive or Cubecraft.

The screenshot showing the error is from one of my friends' screen.