Most robot vacuums come with an auto-recharge feature. When the battery gets low during vacuuming they can automatically find their way to the charging dock.
If your robot vacuum can’t seem to find the dock and keeps wandering around until the battery dies or it gets stuck, it could just be a quality problem that you can’t do much about.
But before you blame the manufacturer make sure you’ve positioned the charging dock properly. If the dock is on a rug, a dark floor, near the stairs or under furniture, it will make it more difficult for the robot vacuum to dock.
The dock should be placed on a hard flat floor in an open area with adequate clearance from the walls and any furniture.
Try moving the charging dock to another place and see if it will work.
If your robot vacuum has been working fine and then suddenly refuces to dock, it could also be a problem with the sensors. Check if the robot is having trouble too navigating around the house. Maybe it is cleaning haphazardly or bumping hard into obstacles.
Clean the sensors and if that doesn’t help, get them replaced.