Mop pads falling off warning

The vacuum keeps saying the mop pads have fallen off, but they are clearly still on. I. Reset the vacuum, cleans the sensors, switched out the mop pads, but nothing seems to work. Help!

Had the same issue with my X40 Ultra. Letting the machine "rest" for a day (!) helped for a while, but I eventually emailed support who had me send it in for repairs, which took about ten days. All better now.