Cannot join friends' worlds

I cannot join worlds that my friends have invited me to, or ones I can join since they are friends only/friends of friends.

Reproducing the issue:

1. Open Minecraft.

2. Log in to your microsoft account.

3. Press “Play”.

4. Join a friend’s world, either through invite or the worlds tab.

Expected result:

A box titled “Connecting to multiplayer server” will appear, with “Locating server” displayed inside the box, above of an animated set of bars. Eventually it will say “Loading resources” and I will have joined the world.

Actual result:

A box titled “Connecting to multiplayer server” appears, with the same animated set of bars, but no text. I never join the world, instead timing out with the error message “Kelp” (referring to timing out). After being kicked back to the “Play” screen, the buttons for joining somebody else’s world in the worlds tab and friends/social menu will do nothing when clicked, playing the sound and animation but doing nothing apart from that. This issue is fixed when I leave to the title screen, and open the “Play” menu again, except the same result happens and I never join the world.

This seems to be a problem no matter what platform I’m joining. I’ve tested joining someone on an xbox and someone on PS4.