A:Answer Hi - We are so sorry to hear about the issue you're having with this model and your previous unit. If you place this unit on your countertop or a small table where you have 3" air clearance on the left and right sides and at the top, as well as 1" clearance in the rear, does the intermittent operation continue to occur? If it doesn't, there's a possibility the microwave when installed in the previous manner may not have been getting adequate airflow which can result in the microwave shutting down. If it does continue, an issue has developed with your microwave and service would be needed. If you have additional questions or concerns, please reach out to us on Social Media. All our best! Vikki@GEA