Thanks for the reply. I am unable to connect to the server via the Android app or the web browser. I've uninstalled Media Server, restarted, and reinstalled it. I removed the server and Rokus from Devices and reclaimed the server. I also removed Plex from both Rokus, rebooted them, then added Plex back.
The Rokus are connected by Ethernet, a means by which I cannot test other currently available devices.
My latest efforts yielded the same thing only more predictable. I'm getting a proxy connection because a "direct connection is not possible". This go 'round is much faster and stable than my previous connection, though.
For the time being, the server is the only computer on the network. We have 2 Android phones and an Android tablet. I'm going to repurpose the old server but have not had time to do it.
The only other thing is if I switch from DHCP to static IP addresses. Everything is "seeing" everything else and the new server is configured the same way as the old one.
Another odd issue is remote access. I've forwarded a range of ports but when I try to get Plex to connect for just a second I get a green icon beside Remote Access then it turns red again. Manually specifying a port brings about the same result.
For now anyway it's working reliably allowing unsecure connections only on the same network. When I have more time I'll fiddle with it some more.