This is what I did, I waited one week and then emailed USCIS just to tell them that my mail has been delivered to you guys on this date, and now you need to acknowledge that mail and send me verification please. They responded to that email that their scanners were not working and they had a lot of work load and they will scan and acknowledged my RFE asap. And after two days they did send me RFER. 😮💨 Now less stress and I'll have to wait for a positive decision soon . Max 30 days