I have never been able to lap a hard stone on a single sheet of wet and dry. A hard stone takes several evolution or addition of loose 60 grit to get to flat. A single sheet of 80 girt would quickly be worn out.

You may want to check your stones.

Mark a grid with a sharpie, put a sheet of 1,000 grit on a flat steel cookie sheet and do one lap on the wet and dry.

If all the ink does not come off, you are not flat. Pencil wears off just with the slurry in a few laps.

A Chinese stone will quickly eat a diamond plate, they pull the diamonds out.