1. I develop a Nikon NEF file. Doesn't matter what I do in this step, even if that's just develop as default.
2. I crop it. My subject is square so I normally crop 1:1.
3. I use the mesh warp to bring the corners of my square subject to the corners of the crop, but if I accidentally click and miss the corner (say, I click below and right of the lower right corner), then clicking again to pick up the corner and dragging the corner no longer adjusts the image. Cancelling the mesh warp and trying again does not work. The mesh warp remains fully nonfunctional unless I close Affinity Photo and start over. Closing the photo and trying again does not work.
If I don't miss clicking on a corner, I have no problem, but if I miss the small square, it causes the problem.
Windows 10. Affinity Photo 2.04, HW acceleration on.
Problem did not occur in Affinity Photo 1 (any version that I've owned).