Pinholes are often caused by either a contaminant on the surface, or too much moisture in the air during painting. My guess is (based on prior experience) that some of the release material is still on the surface, and the pinholes are a surface tension issue. The only way to really fix it is to completely sand down the surface and then use a solvent cleaner to remove any surface chemicals that ought not to be there. Then try spraying a small area to see if you’ve cleaned it enough.
In my experience, if it’s a chemical contaminant causing the pinholes, more primer coats or even filler will not work very well. I learned that the hard way after hours of trying to fix a finish and then having to start over.
Good luck,
Tony