duster rear window rubber wavy inside

So far 2 people locally have told me the gasket I used is the problem , it is a white green bag with mopar authentic restoration product label on it , for those who are interested the heat gun makes it worse , it just makes the rubber really soft and droop down more , just letting it sit seems to be getting better overall after a few days , i ve taped up lower sections of the wave to encourage it to stay up but will change the tape every 24hrs(leaving masking tape after a few days the glue seperates and is very hard to clean off , sometimes the tape doesnt even come off clean , it just rips and then the glue needs heavy rubbing with solvents like brake cleaner) , doing so to a headliner would be a pita , not to mention the ensuing damage to the headliner...