PPG DP-50 Not Curing

Hello, I am in the process of painting a hood for my Dart. I had it bad blasted then cleaned with Acetone. I sprayed DP-50/ 402 activator mixing it exactly as the label says. I then did 2 coats of K-36 high build primer. Then blocked it out. I then sprayed DP-50 again but reduced with DT-870. Normally it would be ready for color in about 20 min. Last week I applied my Omni MTK single stage and after 4 days it still wasn't cured. So I sanded it all off and redid it thinking I did something wrong. Tonight the same issue came up. I applied the DP-50 again as a dealer and after 8 hours it gummed up my sand paper (I had a few dirt specs in the sealer) so off it came again. Is it normal to wipe off epoxy paint with acetone on a rag? I thought it would have a better cure then that. Any ideas why this primer won't cure? Any help will be greatly appreciated.