Try your planes for sharpness before you strop. If they are really sharp before, you are probably rounding over the edge on the strop (I was for a while).
If they aren’t sharp, go back to coarse and make sure you have an even grind on the face, even if you start to get burr you still need a flat, even grind on the whole face.
I tend to remove burr on each stone as I go, rather than use the strop.
Work up through the grits. each grit need to remove the coarser grinding marks from the previous stone, eventually giving you a smooth, mostly shiny but definitely consistent face.
Only then go to your strop.
Hope that helps