Client can't find the server

Installation of the server went ok and seems to be running fine.

But the app can't find the server. I've tried manual entry and still can't find it.

Running the server on a windows laptop, client is an Onn box, but also tried it on my phone with the same result.

Using T mobile for internet service (and the T mobile gateway is also the router). Could this be the issue? I'm running Plex with no issues and all my devices find it just fine.

UPDATE:
It's definitely the windows firewall. I turned it all off and channels connected fine. So how do I allow channels access?

Probably windows firewall

Either just leave it off or create a rule that allows 8089