My new Glock 17 has a takedown lever that is very resistant to use. When trying to pull it down, only one side of the lever moves, sometimes only halfway. The other side seems stuck but will move sometimes. It seems like one side of the lever is sticking out of the frame just barely enough to be noticed. I know the RSA is not out of place. The gun has yet to be fired. What's going on here? Is it just because the gun is new? How can I loosen up the lever?