the problem is the sikkens base , the base is very prone to" lifting "the clear on re-painting. to keep this from relifting , sand back smooth with @600grit . then spray base real dry coat after real dry coat again to seal the edges of your base to clear feathered spots . or you can use some base-fix to seal the areas you sanded thru the clear .
when sanding to repaint try to keep from going thru the clear into the base .