Jellyfin can't see second hdd

[Unknown_147]

Installed jellyfin in docker(ubuntu), {apps we don't talk about - TDP}... using a youtube tutorial and a script everything runs as it should all programs can access their dedicated folders only jellyfin can't.
I have separate hdd just for this media server.
Tried to give jellyfin permission as but it says user doesn't exist. I literally went through all forums i could find and tried everything people said worked for them and still nothing.

I have no idea what to do
Hdd can be formated if that will solve anything(it was used in windows pc before this and not formated) also this is new pc so if reinstaling ubuntu will solve anything it can be done there are no important files.

[TheDreadPirate]

Does the drive in question have an ACL applied? On the command line, when you check the permissions on the folder there will be a "+" at the end of the permissions.