Bummer is all I can say... I could not live with that. Fix it right or take it back!
That said, what is going to happen is as you drive that loose section is going to vibrate and shake going down the road. The turbulence of the air flow is going to work it. Even if they glue it, the glue would need to be injected in many holes to keep this from happening.
Eagle Cap folks should replace the unit or pay to get it back to the factory to make it right!
Other EC owners have posted here that their's are not loose. So yours should not be loose!
Be nice to EC folks and I am sure that they will make it right, the right way!
Jim