I have an iphone 7S and got this bug. I tried updating to ios 14.3 which failed and the phone then had to be reset to factory settings after which ios 14.3 installed and so far everything seems to be back to normal. No idea how I got this bug.

I spoke to soon, it still fails with ios 14.3 with iphone 7 though so far less often

Does anyone know when Apple are going to issue a fix for this bug? My iphone7 now has no cell phone access and I have tried all the fixes recommended. Apple support just told me to contact my sim card provider which I know is not the issue.