ice despenser

I had been noticing frost buildup around the ice chute area on the inside of the freezer. I looked at the chute from the outside looking up and can see a very slight gap. I don’t think it is closing shut all the way but don’t know why. Is this a common problem? How can I fix this problem? I cleaned the bottom of the door chute just to make sure nothing was stuck on it. What would keep it from closing tight?