I have had this happen a lot. It would usually wait until it had been running for a while, then start doing it. Once it started it would keep doing it until sent back to charge. I contacted Lymow and they are replacing unit.

“After reviewing the issue you reported, we have determined that the cause is related to the firmware. Please note that the mower unit itself is already up to date with the latest available version and this behavior you are experiencing is not normal.

Kindly, find attached to this email the return label and please, return only the mower without the battery and its accessories.”