Barracuda rear window gasket question

[cvraider73]

I took my 1964 barracuda to an auto glass and body shop and had them install my replacement window, Laysons Restorations found and shipped to me. I purchased the gasket from Steele Rubber products and the body shop purchased the locking strip for me.
I was happy with the installation until I looked inside the car and found that below the top corners of the windows the gasket buckled/warped in two places just below the top corners.

The glass and body shop owner told me with time and the sun the buckling would settle into place and would smooth out and lay flat like the rest of the gasket.

Is this true or false?

I attached a picture showing the installation as it is today. I tried to zoom in but it might be a bit blurry.

 

[RedFish]

I don't know if it will lay down or not. Time will tell. We've seen 2nd gen stand open, showing the headliner teeth all the way across the top. I think this is why factory service manuals say install the glass from top down. Make the top and sides look right. Any slack and buckling of gasket will be at the bottom, thus not so obvious. Good luck with it.