Disconnect the cable at the front break. Squeeze the proper brifter. Note how much cable travel is evident. Compare that amount to the cable movement to you bicycle. (you do not have to diconnect your bicycle's brake because you know it works,) This will isolate if the problem is it the break itself or the brifter and oc connecting cable. If theamout of cable movement is similar, try compressing the disconnected break to see if is binding. also note how muchmovement that the break will do and how it compares to your bicycle.
If the problem is not in the break, isolate the cable and see if it moves. Or see if the brifter can actuate thecable. good luck