If you have the new FireTV-4K or you're running the new Fire OS 6.2.3.2 and are having problems with mouse toggle here is an easy work around. Just install mouse toggle 1.0.6 and everything works again. If for some reason you're having problems go to settings/My Fire TV/developer options, and turn OFF & ON your ADB debugging & everything should work. (Don't pay attention to the Status it will always just say Starting)
---Mouse Toggle Key Refresher---
Turn on mouse toggle--(Fast Double Click the play button)
Turn off mouse toggle--(Click play once then any other button)
Scroll screen up---------(Hamburger Button)
Scroll Screen Down-----(Fast Forward Button)
Mouse toggle 1.0.6
---Mouse Toggle Key Refresher---
Turn on mouse toggle--(Fast Double Click the play button)
Turn off mouse toggle--(Click play once then any other button)
Scroll screen up---------(Hamburger Button)
Scroll Screen Down-----(Fast Forward Button)
Mouse toggle 1.0.6
https://drop.download/dpi5v5iwaysz