The cleaner leaves the same area unvacuumed each time. There is no apparent reason for this. The area is under a sofa where it clean halfway then stops.
what can I do to get it to vacuum the complete area?
Sorry for the late reply.
How high is the bottom side of the sofa?
We have seen that sometimes the bottom side of beds and sofas sag, and the robot might see that as being too low. The robot might avoid the area to prevent getting stuck.