Problem Opening Step Sequencer 2 Clips with Drum Map

When opening an existing step sequencer clip that is assigned to a drum map a brand new empty step sequncer clip is opened instead of the existing one. The old clip still plays but can not be edited by clicking on the clip. When opening a clip without a drum map it works fine and it is possbible to edit the clip. I am using X1C but not expanded. Thank You for any advice, glc.