There is a problem with the sensor for Y-axis.
Please turn off the device and follow the steps
1. To check the sensor, adjust the bed as shown in the picture below.
Move the belt marked in the picture to pull the bed plate down.
Pull the belt in the direction shown in the picture.
When the bed moves down to certain level, pull the bed plate .
Check the Sensor behind the Bed Plate.
2. Please check the status of the Sensor
1) Please make sure the Harness is well connected.
2) Please remove anything stuck in the Sensor detector part
1-1) If the connector is disconnected, please connect it and reboot the printer
2-1) If anything is stuck near Sensor detector part as shown in the picture, remove it and reboot the printer.