Replaced a steel door on a condo today with a fiberglass slab. Cut door to fit opening, shimed bottom to set in opening, marked existing hinge mortices, removed door and using hinge jig routed in new spaces. Installed old hinges and hung door. Door fits opening well but last 1-2 inches of closing causes hinge to move and you have to apply slight force to close door. Messed with shimming for couple of hours but still have same issue. Will take belt sander back tomorrow to see in hinge side is not true. any other advice