Could be that the paint is on very thick and hasn't had a chance to fully cure under the surface yet. We had this happen during a job where we requested high-gloss paint and a min. of 5 days for outgassig/drying. They slapped on the paint very thick and our murals were failing within a week while murals on the same media on sintra elsewhere in the store were perfect. It took some detective work to figure out about the paint...it was very thick in some spots and while the surface was dry, it was still tacky underneath. About the only you can do if this is the case is to wait....you may need to use some spray adhesive if you plan on using the same graphics to get them to stay on properly.
Wall prep is everything, needs to be smooth, high gloss paint(semi-gloss minimum) and needs to dr for at least 5 days (preferably longer)
By the way, I always use 3M IJ180C for long term large murals (print) and am now using IJ40c for mid-to long term smaller murals (also print). They cost a bit more but out of hundreds of murals we've done, we've never had a failure due to the vinyl and for us and our clients that worth it's wait in gold.