Scroll Bars are MOVING (all artboards & layouts) AUTOMATICALLY

My scroll bars are out of control and have a mind of their very own these days.

1] Any window in any application will automatically scroll to the left or the right or up or down if I hover over the scrollbar. I cannot stop it once it starts.

2] If I create a new layout document where scroll bars are integrated into the window of the application - InDesign, Photoshop, Illustrator (not limited to these) the artboard will automatically move left or right to the edge of the canvas area (my artboard will not stay centered).

If I head to the system preferences and go to either "Trackpad" OR "Mouse," and I toggle (on and off) the Scroll Direction: Natural, that causes the direction of the automatic scrolling in my application shift direction.

If I go thru the "Accessibility" System Preferences - and I toggle (on or off) the "Ignore built-in trackpad when mouse or wireless trackpad is present," there is no change to the movement.

In all cases, the movement stops if I tap out of the application and into the finder - a temporary freeze of the window until I return to it.

3] Grabbing a scrollbar and attempting to move it manually is sticky and freezes. It seems it is more a click to a point in the scroll column - rather than what is normal - an ability to naturally roll along with the mouse. I can "grab" and move a scroll bar for a short distance before it stops/freezes.

Web browsers seem unaffected by the auto scrolling issue - i.e.: Typing this, none of my scroll bars in Chrome are automatically scrolling in the same manner. But the scroll bar is sticky and does freeze when trying to naturally move it around.

This is really creating a problem with trying to get work done. I'm grateful for any help.

Things to know:

MacOS Big Sur Version 11.5.2

MacBook Pro (15-inch, 2019)- with a trackpad

Processor: 2.4 GHz 8-Core Intel Core i9

+ Non-Mac Wireless Mouse (Anker's Vertical Hand Position Mouse)