Summary
On my 10vs10 published UEFN map, the matchmaking system is creating separate single-player server instances for every player who queues up. Late-joining players (backfill) are not being merged into existing active sessions, causing players to play alone despite a high total player count.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Assets
Steps to Reproduce
- Set up an island with 3 teams (Team 1 for pre-game lobby, Team 2 and 3 for 10vs10 gameplay).
- Set “Join in Progress Assigned Team” to Team 1.
- Enable Matchmaking Backfill.
- Publish the island and have multiple players queue up publicly at slightly different times.
Expected Result
Players queueing up should be merged into the same active server instance up to the player limit (20 players) to fill the teams.
Observed Result
Every player who joins gets put into their own separate server instance alone, resulting in multiple isolated lobbies with 1 player each.
Platform(s)
All Platforms (PC, PS5, Xbox, Switch) / Server-side issue.
Island Code
8822-0063-4868
Additional Notes
I suspect that using Team 1 as a dedicated Pre-Game Lobby while setting “Join in Progress Assigned Team” to Team 1 might be causing the Backfill matchmaking system to glitch and lock the server session.