Are you using a bookmark for Jellyfin? If so, what is the bookmark? I've seen people bookmark the setup wizard URL, which results in what you are seeing. Also, are you using a password manager?
Jellyfin 10.10.7 (Docker)
Ubuntu 24.04.2 LTS w/HWE
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
4x WD Red Pro 6TB CMR in RAIDZ1