BTT - Click Type in Custom Mouse Buttons Reverts to Left Click

Describe the bug
When using the Action "Custom Mouse Buttons & Modifiers" when I change the Click Type drop down to anything, briefly shows my selection (Middle Mouse Button in this case) and then immediately switches back to Left Mouse Button. If I click save, in the "Actions assigned to Selected" pane to the left does show middle click + shift. However, if I go to my application that I am trying to customize (Autodesk Fusion 360 in this case), when I push my trigger button (Button 4), I can see the action is performed briefly as the application changes my cursor to indicate it invoked the desired function (Orbit).
But it is only a split second. I would expect that as long as I hold down Button 4, that my application would see a Shift+Middle Button press so that when I drag the cursor the application orbits, and then returns to normal when I release the button. I get this type of behavior in kensingtonworks, when it does work, that software is a bit less than stunning. I was hoping that I could replicate the behavior in BTT and leave kensingtonworks out of the picture entirely.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
"Normal" Bluetooth mouse (Kensington Profit Ergo Vertical Trackball).


Device information:

  • Type of Mac: MacBook Pro (Retina, 15-inch Mid 2014)
  • macOS version: 10.15.7
  • BetterTouchTool version: 3.558

Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.):