What operating system is Jellyfin installed on? And what install method? Most install methods will preserve your existing install. Only a mis-configured Docker install will lose data.
Jellyfin 10.11.11 (Docker)
Debian 13 w/Xanmod amd64v3 LTS kernel
AMD Ryzen 5500 w/32GB DDR4
Intel Arc A380
OS drive - SK Hynix P41 1TB
ZFS Storage pool
vdev1 - 6x WD Red Pro 6TB CMR in RAIDZ1
vdev2 - 3x WD Red Pro 18TB CMR in RAIDZ1