@bemwy,

Do you have more than one network device(router, AP, REs, Switches, or even VLANs) in your network? 

It is possible that the APs are isolating the traffic so that the devices cannot see each other.

First, Check to see if you can update the firmware of your device, as you look to be using an older firmware.

Are you able to ping the IP address of the server from the PC you are using? This would let us know if it can at least see the device/IP on the network.

I would try to also see if this extends to two wired devices seeing each other on the network.