Fedex Delivery to NSC

My I-485 package was sent on Sept. 23 (last Friday) and it was delivered to NSC on Sept. 26 8:30 AM (This Monday). But, on the tracking information, it is said that "signature release on file", and no one signed the package. My lawyer didn't request "signature release", and I called Fedex, they told me that NSC filed a "signature release" with Fedex for incoming packages. My check has not been cashed so far, and I am worrying about my package. Does any one have the same experience to share?

Thanks!