If there is no obvious reason for this (such as pets walking around or furniture having been moved), this is due to a navigation problem. This occurs when the robot's wheels on one or both sides turn without covering any ground, for example if they have got stuck on a high-pile carpet or in front of an object (like a clothes horse or rocking chair) and the wheels are still turning. This is similar to when a step counter designed to show a route counts steps without going anywhere – it leads to problems with navigation. The same problem arises if the robot is moved by more than 30 cm during a cleaning program.
Therefore, before starting a cleaning process, please make sure that the furniture has not been moved (it is best to raise chairs from the floor), that pets are not diverting the robot and that the high-pile carpets or anything on which the robot can get stuck onto have been enclosed with No-Go Lines. In case you momentarily stop the cleaning process, make sure that you place the robot back almost in the same spot where it was stopped and facing the initial direction it was cleaning.
Therefore, before starting a cleaning process, please make sure that the furniture has not been moved (it is best to raise chairs from the floor), that pets are not diverting the robot and that the high-pile carpets or anything on which the robot can get stuck onto have been enclosed with No-Go Lines. In case you momentarily stop the cleaning process, make sure that you place the robot back almost in the same spot where it was stopped and facing the initial direction it was cleaning.