Dragging switches active document focus

While dragging around the image using the space bar, releasing the left mouse button will switch the currently active file window to another one that's underneath it. 
I've noticed it happens when windows are not docked and occurs more often after updating to Photoshop v.25 (but I had that issue on previous versions as well).

One way to deal with it is to minimize every other document I'm not currently working on.
I'm on Win10 with multimonitor setup, installed Wacom tablet drivers (used old ones for Intuos 4 PTK-840 as well as the new release, no change in behaviour was noticed). 

In the video I've attached I caught it when one of the files is maximized but I'm very often experiencing the problem when both windows are smaller than max as well.

Another, perhaps related issue, is that the focus will sometimes switch in a similar manner when using the Ctrl+T transform tool - moving the object would result in a file in window underneath becoming the active document.

I've tried resetting preferences - it solved the sticky space issue but not this one.