For people that have not received a reply this might help.
I sent in the application on 04/03/2019 (Chicago lockbox) and they received it on 04/05/2019. However, I heard nothing until 04/25/2019 when the check was cashed (no texts/emails/NOAs). I spoke with USCIS today and the lady informed me that the NOAs were mailed out on 04/24/2019 and also gave me the receipt numbers so that I could track the application. She did say that 20 between receiving the application and mailing NOAs is not uncommon.
Manav91 got a reaction from araxoolie in April 2019 AOS Filers(merged)