Hey Flak,
I have been experiencing this issue on my new map for a couple weeks now too. My map name is Midnight Massacre Halloween FFA (8942-1492-2947). It tries Finding Server for about 35 seconds and then throws a Matchmaking Error #1.
FortniteGame.log (14.5 MB)
FortniteGame-backup-2025.10.31-20.24.53.log (8.9 MB)
FortniteLauncher.log (552.4 KB)
I have attached the logs you mentioned from trying to join a Public match on my map, of which was unsuccessful. Hope this helps and let me know if you need any additional information! Thanks.