The issue is the entire truck is having fish eye problems,not just that one spot. Once it started to occur I tested areas all over the truck.
I hate to say it, but you'll probably need to sand down the entire body area and clean it thoroughly before repainting. Something causing the fisheyes has settled into the low spots (valleys) of the CARC...you've undoubtedly noticed how rough the CARC application is, it is obvious in your photos. Take a sanding block and some wet-and-dry sanding paper (to keep the dust down, that CARC is nasty stuff) along with a water hose, and smooth out the body areas. Then use a pressure washer with good degreaser to thoroughly wash down the entire vehicle, and pressure-wash off the residue. After allowing to dry thoroughly, probably a couple of days, try your DuPont again. You may even want to wipe down the body area with a good prep solution recommended by the paint vendor prior to painting.
I like to use the Purple Power degreaser from WalMart and other auto parts stores...it breaks down oil, grease, and other residues and works well with pressure-washing. YMMV.
I've also found that enamel is typically the most finicky paint type to apply...yes, lacquers are "hot" and will eat through lesser paints below them, but urethanes and acrylic-based paints I've found to be pretty forgiving for the most part.
And no doubt you've got to compensate for humidity; I take it you've got a moisture trap inline as well as another mounted to your spray gun?