Could be any one..... or two things of 1/2 dozen things that went wrong.
* Do you have much humidity there in texas ??
* Can ya find an old empty can of the paint used ??
* Do you know exactly what vinyl was used ??
* Were there any flaws in the paint before starting ??
* Do you know the painter's procedure as far as primer and how many top coats along with how long between coats ??
This same thing happened to us years ago, but it didn't involve vinyl. We were putting PVC panels up on a wall using VHB and schmootz. We used the same method for hundreds of these things over the years. Suddenly, about a week after we put some up in this particular store, the people called us and told us our installation is failing. We're in PA and this happened down in lower Delaware. I hadda drive down and go up there and inspect the signs we placed around. Some hadda be replaced due to falling and hitting the floor. Thing is, signs at a lower level, were fine. Also signs at two other walls were also fine. Just this front wall and part of the side wall. I investigated and went above the ceiling and looked down. There was NO insulation at all in the front or side wall. The side wall got all the morning and early afternoon sun, while the front wall got the sun all morning and afternoon until it went down. The wall was heating up and then cooling down creating so much moisture back there and along this wall, the signs didn't have a chance. I reported on this and the contractors quickly became my enemies..... because, they were contracted to insulate these walls and because no one would ever see it, they skipped thousands of dollars worth of materials and more money saving on labor of not doing it. They got in a lotta trouble. Anyway, it took them a while to fix their problem, but we had to give it another 2 weeks before we could go back and rehang the 'new' signs. They also paid for the replacement signs and our trip down to hang them and the rental of another scissors lift.