Jellyfin app working but findroid not

[Mat Bailie]

No. I can enable and disable offline mode, and there are no media files either way.

[Mat Bailie]

Also, if I open Findroid without the server running (or just unable to see the server's ip address), I get "Error loading data".

I don't get that message when the server is running, even though no media is listed. Implying that it's successfully connecting, but then "something" prevents it from listing the media.

[TheDreadPirate]

I just realized something. Do you only have music in Jellyfin? Findroid is a video app. Does not do music or audio books.

[Mat Bailie]

Correct.

I suspect that's the OP's issue too