I’ve found that air pathways in the head unit (where the roller is located) get badly clogged about once/year. This usually results in a complete lack of suction and the red thing doesn’t ‘twirl.’ Take the head off (there’s a grey button to push to release it) and examine it VERY carefully. Very long tweezers can be helpful to remove any hair balls or other junk that’s trapped in the air passages. Put the head back on and try again. If no luck, remove and look again. I had to do this 3x before I located the mass of hair and dirt and other junk that was clogging the passage. After that, the vacuum was back to working perfectly.