I never left it outside, it’s been used maybe 30 times, always cleaned, dried and stored in garage after every use. It was never been abused. I liked it so much I bought the next size up, it has not started to delaminate yet.
Mine has the exact same problem. probably 4-5 years old. Don't use it daily, mostly during hunting season. It just rides in the back of the ranger. always washed and stored in garage. No clue how to fix it. Some type of 3M glue sounds like a good idea. I just planned on using it until it completely falls apart and then replcaing with something similar.
Shoe Goo should work. Unfortunately most, if not all of the soft coolers should be stored indoors. The prolong heat while being kept in garages and sheds will eventually break down the adhesives used along the seams. Same goes for expensive wading boots and waders.
Had same thing happen, used e6000 to repair, did not work failed to adhere to the fabric the cooler is made of. Read some comparison reviews of yeti vs engel vs rtic and this delamination problem is a consistent problem for the rtic