I really wish I’d recorded this tech support call
I’ve got a CPAP, it’s a ResMed 10. The SD card failed a while back and I really have not been paying much attention to the sleep tracker because, well, I use it. It failed so long ago I remember having a conversation with the doctor that it just didn’t matter due to the cell backup.
I noticed the other day that there was no data since mid-April in the app. There was also no cell signal to the device.
My bet is it was the 3G Sunset. Spoiler alert, it is/was.

I called up the CPAP provider and asked if this was LTE or 3G. They told me it was LTE (it’s not,) and that when I took the entire machine into my appointment and the doctor accessed the SD card it would reset and fix it (it won’t.)
This was a fairly long call to a company specializing in supporting these. The person repeatedly assured me my pulmonologist was going to be the person to fix it. I shot her a note with the details, she’s not going to fix it.
This is the same company I had to block some of their numbers because they would not stop calling to attempt to sell me CPAP supplies.