ES-210 Blower Throttle sticks

My ES-210 handheld blower throttle sticks in fully closed or open position if I remove the handle and reset trigger, linkage and throttle plate it works fine. When I finish and put it away and come back next time throttle plate is stuck closed. It seems problem in carburetor throttle plate, but don't see why it should stick so hard that it won't move with trigger. I don't want to replace carb to find out its linkage or trigger wear. Has anyone had this experience before.