Showerthought: spent 4 hours chasing a fisheye on a 2019 Civic door before I found it
The panel kept waving at me no matter how many times I went over it with the DA, and it turned out my sanding block had a piece of 180 grit stuck to the pad that I'd missed after 6 months of use, so has anyone else lost half a day to a dirty block instead of the actual metal?
Are you sure it was the block causing the wave and not the door skin still moving under the filler? A stuck piece of 180 would leave scratches and pigtails, not a panel that keeps waving after you level it. I chased the same ghost on a Civic quarter once and it was the panel bonding adhesive letting go, so the metal was flexing every time I leaned on the DA. Check if the wave moves when you push on it with your palm before you blame the block.