Hi Jordan
My experience, several years ago, with POR15 as a base coat was that had to have the special Tie Coat primer used over it to get primer and top coat to stick. But now when I check the Por15 web site
https://www.por15.com/All-Products-Category does not show it. So I'm left to wonder if they have changed product? Will watch with interest how you proceed.
Cheers Phil