Update on this issue:

It turns out that I was the luckiest guy for one day. I found out that the battery pack had unfastened from the velcro strap and was dangling towards the rear of the plane. It threw the CG back more than 2". It was only secured by the connection to the power switch. Any harsh movement would have disconnected the battery in flight and I would have lost this kit built bird. I corrected the error and now the elevator issue has almost disappeared. Phew!