90% chance it was the exup valve. Take off your lower fairing and the little metal cover that protects the cable mechanism on the exup valve. Then take off the cables, and turn it with a pair of plyers a few times whilst spraying with some silicon spray and this should sort it. If its not just the flap which is sticking, force some cable lube down the cables from the servo under the seat whilst the lower cables are still disconnected. And keep moving them in and out.