I am unaware of any issues with the Aera 660 that are similar to what you are experiencing. The best way for us to help you is through our G3Xpert product support team. If you send an email to the address below, we can help you with troubleshooting steps to figure out what is happening and ensure that you end up with a product that works properly.
Garmin G3X Support
1-866-854-8433 - 7 to 7 Central Time M to F
Please email us for support instead of using Private Messaging due to the limitations of the latter.