Let's see what we can figure out. As noted on the Zinsser Bulls Eye 1-2-3 Water Based Primer label, surface must be clean, dry, sound and free from dust, dirt, excessive chalky material, grime, grease, oil, wax, mildew, wallpaper adhesive, or any contamination that may interfere with adhesion. Shellac contains wax, no paint or prime will adhere to shellac that contains wax, it is an unpaintable surface.
Rust-Oleum Product Support 6