iPhone 12 Pro: Apple logo flashes not steady when doing a restart???

Yes my device is a brand new iPhone 12 Pro. The recent iPhones are not yet on the hardware list for anyone starting a question.

With my old iPhone X, to do a full reset I press briefly Volume Up, Volume Down, then hold Power until the Apple logo appears. That logo stays on during most of the restart (under a minute)

With new iPhone 12 Pro, same procedure leads to a momentary bright flash of the Apple logo rather than a steady logo. If I release the power button at that point, the screen stays black for a few seconds then the logo comes on for a few seconds, and the home screen returns. The phone has certainly restarted and may have done a full reset as intended. As expected after a restart, I have to re-enter my PIN to turn on FaceID.

Quite likely this is the new normal, with restart faster on the faster new phone. But it would be nice to know if that is the case, or if instead I have a problem with my new phone. I am encountering problems trying to do encrypted full backup to my Mac, and there is always the chance that my phone is defective.

I did try holding the power button longer after the logo flash. That had the same effect as holding it for a long time with the old phone: I was asked if I wanted to do a full restore rather than just a restart. But the logo did not come on and stay on at any time while the power button was being held.