Do you have internal DNS set up? I have my wire guard deployed on both of my pihole servers, which have local DNS entries for my internal services, which point back to my internal Traefik container for NAT translations. I know that sounds a bit complicated, but that’s how it works for my environment.
Plex is a taboo topic anymore because of their recent business-focused changes. I personally use Plex as I’ve been a user since the early 2000s with no intentions to learn the nuances of Jellyfin, and get my remote streamers moved over to it.
Plex mixed with Sonarr, Radarr and Overseer fits my needs perfectly.