Running OPNsense 23.1.6-amd64
I just switched out my router for an opnsense setup and followed a few guides on getting plex to work. One of the steps was to set plex.direct as a private domain in Services > Unbound DNS > Advanced.
I also set a host override:
plex.direct private-domain A (IPv4 address) 192.168.1.150
Now when I'm trying to connect to plex from within my LAN it takes a really long time to load anything and from the Unbound Reporting it seems that all of the docker ip addresses are being tried during resolution.
172-28-0-1.abcdefghijklmnopqrstuvwxyz012345.plex.direct. Pass Recursion NOERROR 58ms 300
2023-04-22 19:26:46 mediabox.localdomain A 172-28-0-1.abcdefghijklmnopqrstuvwxyz012345.plex.direct. Pass Recursion NOERROR 24ms 86400
2023-04-22 19:26:46 mediabox.localdomain AAAA 192-168-1-150.abcdefghijklmnopqrstuvwxyz012345.plex.direct. Pass Recursion NOERROR 139ms 300
2023-04-22 19:26:46 mediabox.localdomain A v4.plex.tv. Pass Recursion NOERROR 152ms 60
2023-04-22 19:26:46 mediabox.localdomain AAAA 192-168-176-1.abcdefghijklmnopqrstuvwxyz012345.plex.direct. Pass Recursion NOERROR 215ms 300
2023-04-22 19:26:46 mediabox.localdomain A 192-168-176-1.abcdefghijklmnopqrstuvwxyz012345.plex.direct. Pass Recursion NOERROR 110ms 86400
Not quite sure what is happening here.
If that really is the problem, you can switch the preferred network adapter in Plex from "all" to a specific one.
However, I wonder where you got that "plex.direct" tip from. See here for an explanation of why that is probably wrong: https://words.filippo.io/how-plex-is-doing-https-for-all-its-users/ , I think you are masking all of Plex's efforts to resolve your internal addresses,
If your plex setup does not work with just a NAT rule for Port 32400, you should check if your problem is DNS rebinding protection for *.plex.direct (I use IPv6, so it works right out of the box). You can disable that like described here: https://calvin.me/plex-with-dns-over-tls/