IMHO, 800 is waaaaaay too much. I hardly sand any more, but 220 or 320 is as fine as I would go. Your stain is trying to penetrate a piece of glass. The grain underneath the forestock is just the more open end of the grain, I'd say.
220 is as far as I go. In fact I ran out of 220 a while ago and have finished the last couple with 150. I didn't notice any difference in the final product.This is what happens when you don't use calipers, MikeBob