Dexcom g6 data not uploading over cellular data

I’m trying to find help for figuring out a solution to why my son’s iPhone 12 does not upload to the cloud while using cellular data. It does fine when connected to WiFi. I called dexcom and they said it’s because the dexcom g6 app is not yet compatible with iPhone 12. It just seems strange that it works under WiFi and not cellular. I can’t find any data in forums talking about this issue. Can anyone help me?

Yes I know this issue. The issue is that your phone has to allow it to be used by cellular data.
If you look on settings you will see the option.
However probably it is not up to date yet to know to allow it or not.
I had this exact issue happen when I got an iPhone X a couple of years ago
It was resolved on the next update.
If you haven’t already, see if you can update the iOS and also see if there is an update for the dexcom and clarity apps.
You need all 3 to be updated in order to use the cloud properly.
It doesn’t really seem to make sense that it works on WiFi, except for that one little cellular data option.

Otherwise you might be stuck waiting for the next update.