Android client can't connect over VPN

[baronvonj]

I have setup an OpenVPN server on my router, and am able to connect to other home servers with my phone (android) on mobile data over the VPN connection. My Jellyfin server is on a Synology NAS, deployed via Docker (as close as possible to the documentation here, but I guess it was written with older version of Container Manager as some screens were different). I also have Emby installed on the same NAS. I am able to connect Emby client from my phone over the VPN connection to the NAS Emby server. The Jellyfin client however says it can't connect to the Jellyfin server. When I hit connect it says "Tried 2 candidates for input, without success" and lists the https and http versions of the host:port I entered. I have configured the same set subnet CIDRs as local network in both Emby and Jellyfin. When I try to connect via chrome browser to the ip:port of Jellyfin, it does redirect me to the /web page, but the page content never loads.