My Cloud Visible on Network but Not Other Wi-Fi Devices

Someone had a similar problem connected a My Cloud through an ATT unverse router. Their discussion is here:
Can’t connect to U-verse HELP

So I installed a D-link ethernet switch between My Cloud and the ATT uverse PACE router. I was able to finally access My Cloud on my Samsung TV. This situation latest for about a half hour but then disappeared part way through a movie.

I can access the My Cloud using the WDMyCloud program on my PC. Using the WD Discovery program, I can see the WDMyCloud as a NAS, my Samsung TV and Yamaha receiver as Media Renderers and my PC as a Media Server. My Samsung TV does show up 3 more times as Device Type urn:samsung.com:device:MainTVServer2:1, n:samsung.com:device:RemoteControlReceiver:1, and urn:dial-multiscreen-org:device:dialreceiver:1

However, My Cloud is now not available to my Samsung TV and Yamaha receiver.

Any more suggestions would be appreciated. Thanx.