FIrst, is the left aileron down a 1/4" from the flap? Ailerons always find a neutral position. If it is not, the issue could be the flaps not both at a true -3. If it is, you may have a heavy wing and need to correct, likely with hinge slotting. Can't really provide more guidance on rigging beyond do some searching here and start over.
I can tell you that with the 10/14 wing it is possible that tightness prevents the flap from reaching the true -3 location without significant force. You are told to push the flap up untill it hits the spar, but you can't see where it touches. In my case, one flap seemed to be hitting the spar, but in reality, the skin overhang was tight in that area and it wasn't trully hitting the spar. I had to bend and tweak the skin overhang some and file a couple areas to get it to smoothly go all the way to the spar. I found this before 1st flight, but shouldn't be hard to address at your point. Remove the flap attach bars and investigate.
In the 10, all the rigging starts with the flaps at -3, so having them hard against the spar is critical. But I think the 14 may have different tooling to set up rigging. Can't help there.
Larry