In defense of the LF Epoxy.
Two things to get advice from your PPG rep.
First; how you are cleaning the bare metal, went to any “off the wall miracle cleaners” lately that have an acid, or cleaning with lacquer thinner or pure acetone? All the above can cause your problem that you are having.
Second and what I believe is your problem but check with PPG as all epoxies are made different.
We recommend the epoxy set for 48 hours before spraying a polyester type primer so the epoxy can get further into the curing process, as the acetone and thickness of the polyester primers can cause a melting type action aka wicking, where the urethane primer will not so we can primer sooner.
Example without writing a book, so you understand.
Acetone is very aggressive but if you wipe the hood of your new car with it, it won’t hurt a thing.
Now wet a rag with it and set it on the hood for ten minutes or so and it will look like paint stripper was applied.
Some points to discuss with the factory rep.