Try this..............

Pick the wing up by the ailerons. Hold only the ailerons. Wing will be hanging down. Can you wave the wing back and forth? If the wing "wags", you probably got no problems.

As you do more of this, you'll want to try for as close a fit along the hinge lines as possible. It's easily done to have no real gap visible unless you hold it up to a light. Flies better. Looks pro.