Island playtesting not working with multiple people

Summary

I have 6 players in my play test group, and I setup a playtesting session. This is nit a uefn session but a private playtest session.
matchmaking fails to connect, giving these random errors:
Unknown error
Matchmaking failed
This tournament has already started

When trying to load the island as a single player the game connects fine.

I dont see any area for feedback on this and need help solving the issue.
2 days ago I was able to play test the island fine with a group of play testers.
Since then I have not made any changes that should stop the game working.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Matchmaking

Steps to Reproduce

Get 2+ play testers
Try to connect to island session
See match making fail

Expected Result

Testers should be able to load into a session sucessfully

Observed Result

Multiple different errors recieved for the match making failures

Platform(s)

Windows pc, Xbox, playstation

Island Code

2588-7358-2045