People scanning is “stuck”

For weeks (pretty sure started around iOS/iPadOS 15) both my phone (13 Pro) and my iPad (mini 5) have been stuck scanning photos.

Opening photos app, clicking on Albums, then People shows “XXX photos scanned”. “To finish scanning your remaining YYY photos, lock your iPhone and connect it to power”. There is a blue button on the bottom of the page that says ”View People Album”.

Despite the phone being regularly plugged in, locked, and connected to WiFi the progress has not moved in almost two weeks.

I’ve tried all suggested tips (reboot phone, disable/enable iCloud photos, etc)… I have tried both “Optimize iPhone storage” and “Download and Keep Originals” on a whim without success. The same situation exists on my iPad.