However:

A) I've not dropped this phone
B) there aren't spares for the OnePlus 10 Pro yet
C) there's no WAY I'd pull a new-ish / expensive phone apart when its still in warranty

I had reasonably prompt responses from the support staff... until I shared this video with them.

For reference, my OnePlus 5 power button failed after nearly 5 years, when I dropped it button-first on a hard edge, which literally shattered the button. A simple repair.

The "repair" notes say that it had the firmware updated, and was "screened", all tests passed...

But they clearly missed my note, and didn't actually check/test the faulty power button.

I tried to be helpful and identify the issue clearly, but alas. 🤦‍♀️