Summary
Summary: Fortnite Public Matchmaking and MMS Backfill Issue
I am experiencing an issue with Fortnite public matchmaking. Sometimes, players end up in a new, empty session instead of joining an existing active session with available player slots. Sometimes, the game starts with no other players, and matchmaking searches for another lobby instead of filling an existing one.
All relevant settings are enabled and configured:
- Island Settings – MMS Backfill: Enabled.
- Island Settings – Join in Progress Behavior: Spawn Immediately.
- Round Settings – MMS Backfill: Enabled.
- Round Settings – Join in Progress Behavior Override: Enabled and set to Spawn Immediately.
- Round Settings – Enable Join in Progress: Configured to activate on Round Start.
Despite these settings, matchmaking does not consistently place players into existing active sessions.
This issue can seriously affect small Fortnite creators. When players repeatedly end up in empty lobbies, they may assume the island is inactive and leave. This hurts player retention and makes it harder for small creators to build an active player base, even when all settings are configured correctly.
Please investigate whether this is a Fortnite public matchmaking or MMS Backfill issue, including whether it is related to FORT-1123601. I would appreciate a fix or an update on the status of this issue.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Matchmaking
Steps to Reproduce
- Enable MMS Backfill in both Island Settings and Round Settings.
- Set Join in Progress Behavior to Spawn Immediately in Island Settings and Round Settings.
- Configure the Round Settings device to Enable Join in Progress on Round Start.
- Publish the island and start a public matchmaking session using Account A.
- Keep the session running with available player slots.
- Use Account B to search for and join the same island through public matchmaking.
- Check whether Account B joins the existing active session or is placed in a new, empty session.
- Repeat these steps several times, as the issue occurs intermittently.
Please investigate why public matchmaking does not consistently place players into existing active sessions with available slots, even when MMS Backfill and Join in Progress are enabled in both Island Settings and Round Settings.
Expected Result
Players should consistently join existing active public matchmaking sessions when available player slots exist. MMS Backfill and Join in Progress should work correctly with the configured Island Settings and Round Settings, allowing players to enter ongoing matches instead of being placed into new, empty sessions.
Matchmaking should prioritize filling existing sessions before creating new ones, whenever the matchmaking system allows it.
Observed Result
Sometimes, public matchmaking places players into a new, empty session instead of joining an existing active session with available player slots. In some cases, the game starts with no other players, and matchmaking searches for or creates another lobby.
This happens intermittently despite MMS Backfill being enabled in both Island Settings and Round Settings, Join in Progress Behavior being set to Spawn Immediately, and Enable Join in Progress being configured to activate on Round Start.
The issue does not happen every time, making it difficult to reproduce consistently.
Platform(s)
All platforms: PC, PlayStation, Xbox, Nintendo Switch, and mobile devices.
Island Code
2413-8204-0052
Video
no right now sent it later
Additional Notes
This issue occurs intermittently across platforms and appears to affect public matchmaking and MMS Backfill. All relevant settings are enabled in both Island Settings and Round Settings, including Enable Join in Progress on Round Start, but players still sometimes end up in empty sessions instead of joining existing active matches.
The issue can seriously impact smaller Fortnite creators because players may leave when they repeatedly encounter empty lobbies. This makes it harder to retain players and grow an active player base.
Please investigate the matchmaking and backfill system, confirm whether this is a known issue, and provide an update or fix. Thank you.