Just upgraded to the new Arris router and PLEX no longer shows up in my media center.
If everything else is working through the modem and your computers and devices are online, it might just be a setting in the Plex Media Server that needs to be tweaked.
Have you gone through the steps at this page?
This is still ongoing. I have disabled all firewalls on my PC and router as well as AV and files play for a few minutes then disconnect. I had zero problems prior to the Arris router.
try factory resetting it?
Which Arris modem/router do you have?
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