This is the perfect opportunity to set up a pihole. Its primary purpose is to block ads network wide but since it is essentially a DNS with a block list you can also set custom dns-entries.
There seems to be a bit of a misunderstanding of what a reverse proxy does.
The proxy should accept requests on port 80 and 443 and on the basis of the requested website route you to the correct adress:
So your client thinks its talking to your jellyfin-instance over port 443 but in actuality your proxy reroutes the traffic to wherever your jellyfin needs it to arrive…
/Edit: Ah just saw that it redirects 443 requests to your router. Can you configure a DNS override on its config somewhere?
AMD EPYC 7B12 / 256GB RAM / Supermicro H12SSL-i / 4x2TB Samsung 980 Pro in ZFS RAIDZ-10
Total overkill for what is currently running on it. But who knows what the future brings.
Current:
Docker-based
As a VM in Proxmox VE
As an LXC in Proxmox VE
Ha, same here. HAProxy plugin running on my opnSense. I should probably try caddy because HAProxy is complete overkill for my requirements.