I've had a Plex server for a number of years, installed on my desktop PC and it has been running without a hitch. Recently decided to get the Spark Smart modem with a mesh unit and now none of my devices are able to see it. This is both wireless and wired devices. I can log into my Plex dashboard and see my account settings there but no options to configure any network settings or anything remotely useful. I do recall logging in and it had a warning notice for me to click on regarding access or something. It started searching then the server dropped off completely with a message I can't remember.

I'm guessing I need to do something with the smart modem settings but I'm a lot clueless when it comes to this so any help will be appreciated.