Why doesn't my Maestro connect to my home router thru Tmobil Galaxy Flip phone?

For the first time I'm trying to use my Maestro outside the wifi range of my Netgear R9000 router by using a Galaxy Flip phone on the T Mobil network.

I turn on my flip phone hotspot and it will appear in the Maestro's list of available networks. I highlight it and click connect. The Maestro apparently connects, but says there are no available radios.

The phone indicates that the Maestro has connected to it.

It appears that phone's hotspot can't access the Flexradio through my Netgear R9000 router. On the router, I have tried turning on "port forwarding" and "port triggering", but neither setting helped.

I have set the security on the phone to "open". I've tried the other security settings on the phone, but nothing helped.

I can access various websites using a PC with the hotspot so the hotspot seems to work. Also, as long as the Maestro is within my wifi range, it accesses the radio without problem.

Does anyone have any suggestions as to how to make the Maestro, hotspot combination access my radio?

Regards,

Jim Charlton AD0AB