PVC roof failure

Yep, same thing happened to us. We replaced the roof on our 2016 toy hauler in spring of 2021 with PVC. I done extensive research on the different materials for travel trailer roofing material. This seemed the way to go for durability, life span, easy repair for unexpected damage. It lasted until summer 2024 and started cracking/crumbling/flaking. Ended up applying rubber roof coating over to get through 2024 camping season and didn't get around to replacing last winter/spring as we had intended so we still just have it covered with the rubber roof coating that we painted on over the junk PVC. It is working but so frustrating with all the work, money and hours we put into replacing it thinking we were good for several years.  The PVC we bought was supposedly the same they use on flat roof commercial buildings, also sold as travel trailer roofing. I belive we just happened to have gotten a bad run of material.  But what do you do when you install it yourself?.? I am sure the company would just say we done something wrong during installation to break the material properties down. All though we bought and followed all the instructions that came with the kit. Now I have to figure which junk material we want to install this time around. So frustrating!