Cotton swab and isopropyl alcohol.

Use a cotton swab lightly dampened with isopropyl alcohol.

The cliff sensors are those little circular cutouts on the bottom. They get dusty or covered in hair, so the vacuum thinks there’s a drop when there isn’t. A dry swab might just smear the dirt around. Alcohol cuts through grime and dries fast — just don’t soak it. Wipe gently, let it air dry for a minute.

Check your manual first; some vacuums have a sensor cleaning mode or specific instructions. But in general, this works for Roomba, Roborock, and most others. Do this every few weeks and your vacuum won’t start backing away from thin air.

It takes longer to find the rubbing alcohol than to do the cleaning.