Well, you previously stated they never responded to the congressional inquiry which is why I felt a need to clarify that claim. If the rep told you it may take 2-3 weeks (which I know from experience could be slightly longer), and this is week 3, I would phrase that as they’re yet to respond, and not they never responded. You can reach out to your Senator though at the end of week 3 to initiate another congressional inquiry (I think Susie earlier on suggested this).
Considering the Chicago Lockbox acknowledged case receipt in early May (yes, you filed as far back as late March, but technically that doesn’t matter while the case is pending acceptance), your AOS case file was sent to the FO on 6/28 (based on what you were told), that timeline doesn’t demonstrate an unusual delay with sending the case file.
The FO does not adjudicate the FTO application, they may not even be aware of your having filed it as a matter of fact. I only brought it up because it is possible when the NBC received your package, someone wrongly assumed your AOS application was family and not DV based once they saw the I-824, and subsequently set it aside as against fast tracking it like DV based AOS applications are required to be handled. I’m equally curious about your case considering yours is the first case of concurrent file of DV based I-485 and I-824 I’m aware of - I can’t seem to recall any other similar case in the past.