When using the Modify Stitch functions, after selecting the function click on the stitch that you want to modify.
When any of the Modify Stitch functions in the Modify tab except Edit Stop Command are selected, the command markers are enlarged to make them easier to identify. (When Edit Stop Command is selected only the Stop markers are enlarged.)
To find a marker, click one of the Modify Stitch functions so that the markers are shown at a larger size, then right-click to cancel the function.