Replace the Automower Metal Skid Plate
The skid plate is a circular metal disc which sits underneath your Automower, its purpose is to protect the cutting disc but it also assist in allowing the cutting disc to spin up with less resistance in long grass. Its fairly common to replace these plates each year especially if its come into contact with objects while cutting.
Replacing will only taka a few minutes. You will need a torx 25 screw driver or bit to unscrew 3 screws which hold the plate in place.
Look up your spares parts here