Very curious about this, as so far, we've only heard reports of it on 12 Pro and Pro Max. Perhaps the stock level for the 12 was such that it took a little longer for it to need to be replenished?Interestingly enough, my wife just bought an iPhone 12 (not Pro), and guess what? It’s doing exactly the same thing!
She’s got an appointment tomorrow to have it looked at. The rep on the phone said they had never heard of this issue before!
As for the reps, their answers have been mixed, from those who've not heard of this at all, those who know of it but think it's perfectly normal, to some who say it's a hardware fault. I'm hoping we'll hear from Apple directly some time this week.