I am not at all sure Snap & Snap Assist are working as they should. I find it rather confusing to sort out what to expect, having read some articles about it (here and elswhere.)

The most obvious sign is that there is no transparent overlay. I have never seen this phenomenon even when trying to activate it deliberately. Next, am I right in thinking Snap should mean that adjacent Windows are precisely 'butted' against one another? Sometimes I get this, at other times they overlap. The 'thumbnail list apears sometimes, not always and when I open a fresh Window from a thumbnail it does not Snap into place, often it overlaps and I have to adjust it manually. When I move a Window to left, right or a corner nothing happens, it just keeps on moving until it goes off the screen.

I use a combination of mouse and the Windows arrow keys. The arrow key method often Snaps when the mouse does not.

I have all the Snap options set to 'on' in Settings.

I anticipated I might have some problems with Snap as my maximum display is1280 X 80, ie. les than the recomended resolution, but I have no difficulty displaying multiple Windows (4).