Container WebGUI/Port 32400 unresponsive after some time of watching

Hi,
I have a problem with my Plex container running on RancherOS. Currently I use PlexPass/Beta version 1.12.1.4885-1046ba85f.
After some time of watching (about 1-2 hours) PMS stops working (not dependent on current video file). When I look into the process list (ps -eF) within the container it is still running, but does not reply to Port 32400. Port ist still open, but I do not get any responses. Also healthcheck.sh is running and keeps running for a long time (longer than the specified 15 seconds timeout I guess).
Now I can either restart the container or wait for about 10-20 minutes. After that the webgui is reachable again and Plex Apps can connect again and play video files.
docker logs does not show any entry to this (stays at):

Preparing to unpack /tmp/plexmediaserver.deb ...
Unpacking plexmediaserver (1.12.1.4885-1046ba85f) over (1.12.1.4871-6daee94e2) ...
Setting up plexmediaserver (1.12.1.4885-1046ba85f) ...

##################################################################
#  NOTE: Your system does not have udev installed. Without udev  #
#        you won't be able to use DVBLogic's TVButler for DVR    #
#        or for LiveTV                                           #
#                                                                #
#        Please install udev and reinstall Plex Media Server to  #
#        to enable TV Butler support in Plex Media Server.       #
#                                                                #
#        To install udev run: sudo apt-get install udev          #
#                                                                #
##################################################################

Processing triggers for systemd (229-4ubuntu21.1) ...
[cont-init.d] 50-plex-update: exited 0.
[cont-init.d] done.
[services.d] starting services
[services.d] done.
Starting Plex Media Server.
Critical: libusb_init failed

I also did not find something useful in Plex Media Server.log
Although only “PMS error log” is activated but “Verbose logging” is deactivated in WebGUI, there are a lot of DEBUG messages in PMS.log. Is this correct?

And additional question: I want to use my PlexPass advantages but I want to run stable version of Plex. Do not need Beta versions. But PlexPass Tag has been removed/redirected to Beta. Can I use PlexPass advantages with the Public Version?
And I thought there has been a stable PlexPass version also (without docker).

Regards
Martin

Okay, tried verbose logging and there are even more messages with tag “VERBOSE”. So DEBUG messages seem to be common.