Plex Media Server uses Avahi and GDM for network discovery, and so generally doesn't work well in docker.
The simplest way to make it just work is to use docker's "host" network mode. I run with:
docker run -d \
--net=host \
akursar/plex
Content type
Image
Digest
sha256:5e2898bfd…
Size
159.2 MB
Last updated
over 5 years ago
docker pull akursar/plex