Honeywell wifi thermostat not able to connect

I was having the same thing at my ranch. Only the thermostat and Alexa were connected. Tried connecting with hotspot and that did not work. I ended up setting up a new wireless SSID (called thermostat so i can remember why) and the only thing that's connecting to it is the thermostat. With T-Mobile there's very limited advanced connectivity but I did set it to 2G and WPA2 only, not mixed wpa2 and wpa3).  Those were the only changes and nothing else on this network and it's now working.