Scroll function broken, Magic Mouse 2

Version 3.404, Magic Mouse 2.
When program is open, single finger scroll non-functional. Sometimes I can get a quick flick out of it, but that's it. Problems persist after deleting all configurations and resetting settings.

Mouse functions normally when program is quit.
Workaround: keeping another finger on the surface of the mouse seems to re-enable scrolling for some reason, but only for vertical scrolling. Horizontal scrolling remains kaput.

I had the same problem today configuring BTT for my shining new iMac and a Magic Mouse 2. I were able to figure out it's some kind of bug which makes 1 finger scroll stop working when having a set of BTT settings specifically for Safari.

Solution: Have no special settings for Safari and collect them all in the "All Apps" tab.