DIAGNOSIS: The infrared cliff sensors on the bottom are being tricked by dark, light-absorbing surfaces. The robot thinks it's a drop-off and backs away.
FIX: In the Ecovacs app, go to your robot's settings, find the 'Carpet Settings' menu, and turn OFF 'Anti-Drop Sensors for Carpet'. This lets it drive over those surfaces. For specific problem rugs, you can also draw a Keep-Out Zone around them in the map.
IF THAT DIDN'T WORK: Check if the sensors themselves are dirty. Wipe the four clear, circular infrared windows on the underside of the robot with a microfiber cloth. A smudge can scatter the light and cause false readings.
HEADS UP: Turning off the cliff sensors means you must ensure the robot won't encounter actual stairs or a significant drop while cleaning that area. Use zone restrictions for safety.