One extra position on front derailleur besides trim
Presumably it is a further trim position if you have double (not triple) shifters, and previously the limit screw was preventing the cable movement. Now you’ve installed a new cable and changed limit screws a bit maybe you’ve allowed access to a high gear trim position. 

My 105 5700 double shifter does the same thing, and I can prevent it from happening by tightening the high limit screw