@Ricliz 

Robot vacuums use radar sensors to scan and map their surroundings. However, surfaces with reflective or transparent properties (like glass, acrylic panels, mirrors, etc) can interfere with the radar signals, causing the device to map phantom areas that don’t physically exist.

If there are such objects or elements in your environment, position reflective objects at least 30 cm above ground level. If the objects cannot be relocated, cover the lower 30 cm portion of the surface with non-reflective material (e.g., fabric, cardboard).

Once the correct map is created, you can save it as a backup.