Got a silent update to the Moto Camera app, and an OS patch up to 1 February 2024 security patch level with the usual "bug fixes and performance improvements" totally-unhelpful patch notes. It's not massively sunny today, but it's potentially fixed. Maybe. I took a couple of pictures outside, with a sheet of paper in my outstretched hand: despite auto-HDR still being forced-on, it didn't fire (no _HDR suffix in the filename.) Indoors, it fired - but a white sheet of paper remained white. Fingers crossed they've actually fixed it - even if auto-HDR *still* resets to on every time you close the camera app...