Connecting Stick up Cams to Hotspot

I have 4 existing Ring systems so this is not my first time setting up devices with Ring.I am sitting at home trying to set up several Ring Stick up Cams to an Android hotspot. Once I have the cameras linked to the phone's hotspot, I will install the cameras on a new-construction home temporarily until it sells. I am having trouble getting the camera to connect to the hotspot. The Cam will "connect to the Ring app". The Cam will then announce it is "connecting to Wifi". The blue light on the Cam goes solid blue (no blinking). The app gets to exactly 95% and freezes for 47 seconds (with several messages popping up). I then get the message "Hmm. Something went wrong" and the Cam announces "Set up did not complete. Check your internet connection and try again." It can't be the signal strength...they are only about 16" apart. I have tried the same procedure using an Apple phone's hotspot (yes I did "maximize compatibility" to enable 2.4G), but the app does not even recognize the hotspot connection at all on the iphone. I am at a loss. What should I do next to get this to work?