Built-in webcam not showing image

[malrobins]

Open 'camera' app, black box but all the icons, controls etc showing.
Little light next to actual camera is illuminated.

Really weird is the little green box which moves about as I move, like it's following me (some sort of focal point thing?)

Click on 'photo', takes photo which I can view on desktop.
Similar take video which I can view.

HP Diagnostics checks webcam, says it is working and even shows me a 'live' picture to prove it.

Updated what I can based on HP recommendations, tried various drivers, etc.

In my opinion the 'link' between the webcam and the app is broken as everything else works.
Presumably Skype uses same tech as Microsoft  as nothing shows in Skype either.

It works fine in a Facebook video call.

All the the suggested Google solutions from everybody point to the driver (including some bizarre ones!!) but I tried them all, including Registry hacks.

Tried clean boot too. And System File Checker.

Wish you could uninstall camera (from Windows) but you can't (did delete in Device manager etc and let Windows find it again).
Out of ideas.
19-06-23 added screenshot of Windows report.

[malrobins]

Found how to remove camera app using Powershell.
Went to Store and downloaded aoo and installed.

Still doesn't work.

Note, and I repeat, works just fine in Facebook video call.