My top was delaminating at the base of the rear window. Took it to an upholstery shop; the tech there said there was no problem with leaks but the window was heat sealed to the top at the factory, and to his knowledge there was no "fix" other than to replace either that section or the whole top. I didn't like that option for what appeared to be about 18" of loose fabric that had no impact other than a cosmetic one.
After reading on this forum and some other forums on cars with convertible tops, it appears a urethane based adhesive is the way to go.
My son worked for a windshield repair guy while he was in college. The guy put some primer on my glass, then applied the urethane, taped the two surfaces together, and advised me to leave the tape in place for 48 hours.
Not sure how long it will hold, but I removed the tape this a.m., and it appears to be holding very firm for now. Time will tell, but at least I have nothing invested, and I think it's going to do fine.
Just an FYI; at least in my area, the primer and the urethane are both available at car paint shops. Urethane was around $19 for a tube that fits in a regular caulk gun; the primer was $35 for a very small bottle. Both would do many, many windows with this problem.