Cannot join the party of a FN client that was started from within UEFN

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Matchmaking

Summary

When you try to join a player that is in a live session as a second player, you can’t. You get matchmaking error and the second player is not shown on the join menu in the POV of the first player either. I tested this with a PC client starting UEFN, then a switch client trying to join them. The workaround is that the PC client has to leave and go to the main lobby, and then matchmaking will work again, but it’s troublesome to do this everytime you want to test MP in UEFN.

Steps to Reproduce

Have two clients with FN installed, befriended and on the same team in creator portal (ideally PC and Switch to replicate my case exactly)
PC client opens up UEFN and loads live edit.
Invites the second player through Fortnite while live edit is open.

Expected Result

Player B (on switch) can join player A on PC

Observed Result

Player A doesnt see Player B on list of friends at all.
Player B sees Player A on list of friends, but when trying to join there is a matchmaking error.

Platform(s)

PC, Switch