I have no Jellyfin running, but as a pointer:
- I expect your clients not to find Jellyfin by IP; either because there is no matching TLS certificate (when using HTTPS) or because the client does not want to connect (when using HTTP)
- workarounds:
- create an A (and perhaps AAAA) record for your local IP at your DNS registrar (ie, jelly.mydomain.tld = 192.168.x.y)
- get a Letsencrypt certificate (using the DNS-01 challenge, the HTTP-01 challenge would not work for local addresses)