Question mobile data spontaneously turns off

[csillver]

Ok, I have a galaxy note 20 ultra 5G. I love it, it does what I need it to do. I use google and bing to make calls, but on occasion, I am told by the AI that it cant make the call until I turn the mobile data on. Now, its always when Im driving and trying to make a hands free call. So its really maddening.
Ive tried:
Resetting the nettwork settings
Rebooting the phone
Factory resets both hard and soft
Turning the data off then back on in various states

This issue is totally random, and sometimes doesn't happen for weeks/ months.
Im with T-Mobile and they have been no help, and basically doing the above steps over and over and ....

Any help or is this a known issue. I have not found it posted here, other forums or general internet inquiries .
Thanks

 

[B. Diddy]

Do you have wi-fi on when this happens? If so, see if the phone is connecting to some random wi-fi network when you see the error message. I'm wondering if it has something to do with connecting to a wi-fi network that doesn't actually have a viable connection, and the phone isn't dropping back to your mobile data signal like it should.

 

[csillver]

Thats probably the most sensible thing Ive heard in a year. The question I would ask however is, how do I keep that from happening? Do I need to shut off wifi every time I leave the house? I have wifi calling because the area I live in is a KNOWN cellular dead zone. We all get service once we leave the area.
and Thank you

 

[B. Diddy]

First, check the phone's wi-fi settings and see if there's an option to automatically connect to open Wi-Fi networks. If so, make sure that's turned off.

Another approach would be to try and catch when this happens on your phone (which I realize can be challenging if you're driving alone). If you find that the phone is connecting inappropriate with a wi-fi network, see what network it is, and Forget it in the Wi-Fi settings.

 

[mustang7757]

How old is your sim card?