Set Server Up On New Router, Now Plex Will Not Open

[darthdan]

When I set up my new TPLink router, I ensured I had port 32400 open as I did with the previous router. I ensured that I had a fixed IP for my server as well. After startup, I went to open Plex, but it would not open. I get a "problem opening page" error in the browser. I can see in the resource monitor that Plex is running, but it's not taking up any resources at all. I have tried to uninstall and reinstall Plex to no avail. Has anyone run into this? If you did, how did you fix it? Do I need to blow up my server and reinstall the OS?

[TMtina]

Please ensure that no other applications or services (such as Docker containers or other network applications) are occupying port 32400. Additionally, you can try clearing your browser cache as old cache data may interfere with the loading of new services.