I run several services not in Docker, including PMS. The Docker Police came to my house, but I just hid in the crawlspace for an hour and they left.
Docker is like bacon. It can be great, but it is not necessary to wrap literally everything in it.
You can do everything necessary to install Plex via ssh. You don’t need a desktop at all. If you can get Plex running properly you can always add a remote GUI later.
Anyway like Chuck said, SIMPLIFY first, and make sure you can access the web server on your LAN.
(The first time I set up PMS on Ubuntu, my system ended up in a weird state where the firewall was badly misconfigured, and I could not reach PMS on the LAN. Somehow, ufw and the underlying real firewall got out of sync. I started over and it worked fine… Still no idea why.)
I too spent several hours setting up on Ubuntu and had to do a fresh install 5 hours in. But my issue was that I went to delete all the files in a folder and accidentally forgot an * and you know… Attempted to delete every file and directory.
Practically a rite of passage. 
I spent some time on this over the weekend. I disabled Wayland, restarted, got it working, then moved it to my router. There was actually only one port on the router, so I connected a small switch I had and connected my NAS and the NUC to the switch. I can access plex within my network, and I am able to access it from outside (I’m at work and it loads just fine). However, it still says it’s not available outside my network after a few seconds of saying it is available outside my network. And when I check the port, 32400 still says closed. I tried setting up Overseerr and it can’t connect to my Plex instance, no matter how I try to reference to it.
One last issue - I can access the NUC using AnyDesk, but it just shows the background image, not the top bar, not the side bar, so I can’t really do much except try to run things from keyboard shortcuts or the terminal. I don’t mind using the terminal, but it seems weird that it won’t show me the entire desktop… Any ideas?
Thanks again for everyone’s help!
Don’t use Plex’s built-in tester. It is misleading. They should really fix it or eliminate it because countless people have been confused by the same thing.
This is the only test that matters.
So this is what I need to resolve. I was hoping that when I connected the NUC directly to the router, rather than using WIFI, that issue would be resolved, but not the case. So I’m not sure how to fix this, beyond getting a new router. I suppose I could try rebooting the entire network and see if that resolves it… Any other ideas are appreicated!
If you haven’t rebooted everything a couple times I always try that before even coming here ha! But @ChuckPa will have the most insight on what may be happening there if you can actually remote stream but that port is reporting as closed.
If it’s possible to get AnyDesk to work,
I’m willing to help out (phone + anydesk)
( I carry an assortment of 
) 
Thanks djfriday13! I have rebooted at least 7 times since starting this whole thing.
Thanks ChuckPa! I work from home Thursday and Friday, so maybe one of those days this week? I can bring the NUC back upstairs and use it on wifi.
Hey @ChuckPa - I’ll have some time this Thursday afternoon (3/28), would that work for you? And how would I get my contact info to you? Let me know, thanks so much for offering to help!!
That works ok for me.
Thursday afternoon your time zone or mine?
Thanks! Since I don’t know your tz, how about PST? I have one meeting Thursday, from 10am to 12pm PST.
My name should be an indication… “Pa” (as in Pa / NY / NJ … 
)
I’m EST
I’m slow, but eventually I catch on… 
Hey @ChuckPa, let me know how we can connect. I’m available any time now. Thanks!
