having the same problem…
Plex is picking the internal address from virtual switch which used for container / linux
station and not the right one…
Or there is an issue with openVPN server when enabled
QNAP by default created the virtual switches in the bridged with virtual DHCP server for VMs when virtualization apps (Linux Station I think) were installed because static IPs on the QNAP interfaces were set. PLEX then detects this virtual switch IP and makes it as a local interface entry into their XML.
Plex needs to enable the owner of the account to specify what IPs are used in what order or disables IPs via the plex.tv website.
Go to your router and DHCP reserve the IP addresses that you want for your QNAP interfaces.
Set QNAP interfaces to DHCP.
Keep PLEX online and enabled during this process.
On QNAP, Shut down the Virtualization Station, Container Station and Linux Station.
In QNAP go to Control Panel → Network & Virtual Switch. Edit all virtual switches listed in your XML to an unassigned or offline port on the QNAP. Deleting the switch straight up with a live connection has issues at times. Technically deleting them is possible, but I had issues.
Once Switches are assigned to down ports, delete the switches.
Create a virtual switch bridged and select the live port and VM adapters.
Restart Virtualization Station, Container Station and Linux Station
This process varies between 4.2 and 4.3 instances if you are using Virtualization Station. You specify in virtualization station which interface to use.
In 4.3 you can do everything via Control Panel → Network & Virtual Switch.
Essentially what you are doing is re-configuring QNAP interfaces so PLEX detects the prefered IP first in their XML. You can refresh your token view page at anytime during this and watch PLEX move the order of IPs around.
Full disclosure, I know how to fix it in both as I upgraded from 4.2 to 4.3 hoping for a solution as I use VMs and Plex from the QNAP. The PLEX app situation was not good in 4.3 due to the trouble shooting I went through to figure this out. I rolled the QNAP back to 4.2 from 4.3 which btw is a bad idea. Deployed the nuke and factory re-inited the entire TVS-882 at 4.2.X and re-installed everything from the ground up.
On QNAP, Shut down the Virtualization Station, Container Station and Linux Station.
In QNAP go to Control Panel → Network & Virtual Switch. Edit all virtual switches to an unassigned or offline port on the QNAP. Deleting the switch straight up with a live connection has issues at times. Technically deleting them is possible, but I had issues.
Once Switches are assigned to down ports, delete the switches.