strange new problem: auto selecting the topmost (visible) layer

Got a fresh install of MacOS since I changed the hard drive to a SSD one, and I installed from zero Adobe CC and my programs.

Since then I have this issue:

- I open a psd file with layers

- I want to move a layer which is not the topmost one.

- Therefore I select from the layer list  the layer I want to move around.

- with the move tool, I click on the image and start dragging

- here the  odd! the selection, in the layer list, switch automatically from the layer I chose, to the topmost visible layer

this doesn't happen if , ie, I use the brush tool and start brushing on a layer which is not the topmost one: it does what it has to do.

I tried to uninstall photoshop and install it again, even choosing to delete the preferences, but it still does it!!!

any help?

thanx !:)