Screenshot not working on IPhone 12 Pro AND iPhone 13 Pro

About 10 months ago I became unable to take a screenshot on my iPhone 12 Pro. I read all the forums and tried every reset and suggestion. Nothing could make it work again. In the meantime me I gave up and decided I could live without it until I got a new iPhone.

So now I have a new iPhone 13 Pro and I still cannot take a screenshot.

I cannot fathom what this can be. Anyone have any thoughts?

Andy