H4 extension docs sent back because of invalid address

Hi all, my h4 visa extension got approved on the USCIS website. But the approved documents has sent back as my mailing is not updated with current address. Also, the status on USCIS site is updated back to initial review. Now I have called them up and requested for address change. I can now see as address has been updated but the status is still in initial review. Any idea how long does it take to make a decision? Is it again go through all the background check process or just that same old documents will be mailed to new address??

Any help is much appreciated!