As I said, 2.11 and the like are not supplied by us. Where did you obtain “Audacity 2.1-4.3” from?
I suggest you trash all your Audacity versions. Next, install an anti-virus app and run the most thorough check possible.
Then go to http://audacityteam.org/download/mac and install 2.1.2. Please follow these steps to install Audacity https://forum.audacityteam.org/t/installation-do-not-run-audacity-from-the-dmg/31711/1
Next, before launching Audacity, open Finder, choose Go > Go to Folder and type:
~/Library/Application Support/
Delete the “audacity” folder in Application Support. Now you will have fresh Audacity settings.
What mouse are you using (make and model number)? It could be you have a mouse lock setting operating.
Do not use the mouse scroll wheel when you are over the Vertical Scale unless you want to scroll up and down the vertical scale. If you scroll or zoom the vertical scale by accident, hold SHIFT and right-click (or CTRL-click) on the vertical scale to reset the vertical scale to normal.
In your video, it looked like you were moving the Mixer Board gain and pan sliders and the gain and pan sliders on the corresponding track were not moving. If so, that is wrong, but I cannot make that happen.
Gale