Plex treating LAN as WAN

[Coxeroni]

I don’t know if this is also applies to you, but there was a user who had problems with exactly this type of certificate:

[Android/FFmpeg] Peer certificate failed verification

I had a similar problem that I discovered was due to an expiring Comodo/Sectigo certificate. See this gist:

Note that I don’t know a lot about these certificates
I just remembered someone mentioned that cert before.