Side Brush Falls Off

Can anyone explain why a company would make a product where they brag about the side brush, yet when in actual use the brush falls off all of the time!

The side brush has a Phillips head screw in the center of it, when you put one on or switch them out. Look to make sure the screw is in place and tightened, and that should solve your problem

How do you add cleaning substance to the mop

My brush has never fallen off. Is it on the vaccum correctly?

Mine has never fallen off either.

Is the GEN two able to navigate a runner between an island and cabinets that’s partial floor and partial runner? it seems to be going back-and-forth and then skipped the whole area.