Changing stitch

[thecompostxyz]

When I go to change the stitch on selected stitches, the stitches on the whole grid change.

Selected stitches were copied and pasted from unselected stitches.

When I cut the selected stitches from one layer and put them on a second and select only that second layer, I try to change the stitches, and all stitches on both layers change.

Can this be changed so that any stitches I select will change to the stitch I want?