The previous advice about thoroughly cleaning is good. My Roomba does have a broken part that causes this though. I’m not sure the correct name but its the hollow hatch that goes over the rollers. It has broken near the middle on the side away from the hinges. If you get it in the right place before cleaning it works OK still though it can be put out of position if the Roomba goes over something it shouldn’t (a cable or something large). Maybe worth checking on yours if nothing else helps. Sadly I can’t find a replacement part anywhere.