I'm not sure how the factory attaches those strips but I've never heard of them coming off like that. One thing is for sure. They need to be replaced with new ones.
If it were me, I would clean the roof surfaces (and the new strips) well with a detergent and finish up with rubbing alcohol. Allow to thoroughly dry. I would use 3M double sided VHB tape to reattach. I'd run a 1/2" (or more) strip on the bottom side of both sides of the strip (lengthwise). I'd snap a chalk line on the roof where one edge is to go. Then I'd lay the strip in place.
If you have a couple of helpers, it may be better to have one on either end of the strip hold the new strip squarely above the chalk line and the 3rd person push the center of the strip down then work your way to either end (be careful to follow the chalk line). There are no 2nd chances. After it's in place, it must be pressed down hard to activate the tape. I'd use a wooden roller. Once in place, it will never move.
Also, be sure to clean your bag seals real well and clean them regularly. I use an industrial citrus cleaner/degreaser from Home Depot.
https://www.amazon.com/3M-Mounting-P...s%2C276&sr=8-4