The robot isn't cleaning the carpets like was. It's leaving fluff on them, it seems to work on the tiles fine. I've cleaned all the filters so I'm not sure what else to do. Even the power setting doesn't fix the problem.
Could it be a problem with the brush roll (the rotating brush inside the main nozzle)? It's needed to whip up the dust from carpets.
You could start the robot and, while it's running on the floor, carefully feel the brush roll from the front, to check that it's actually rotating. (Don't put your fingers in too far - it's not dangerous, but it can hurt some. Speaking from my own experience here...)
If the brush roll isn't running, first remove it and check that there is no hair stuck in the bearings at either end. If that doesn't help, you need to contact your nearest service center for a repair.
Hope it helps!