That is actually longer than usual time for NDVO to send AOR2. May be they have sent it by mail because of which it is taking time. It is also possible that it is lost in the mail.
Since you have already sent an inquiry, you should just wait for now. If you don't get any update in next couple of weeks and really want to know the progress, you can ask your MP to check. Not getting AOR2 is not a big deal but you should confirm the mode through which NDVO sent AOR2. They'll most probably send the PPR also through the same mode and you definitely do not want the PPR to be delayed or lost. Does the PA has an email on the form?
FYI, AOR2 also asks for RPRF and PCC if not already sent. If you have not sent these with your application, you should send them now.