I just found the full timeline of an applicant whose BG status went through the same pattern. On Mar. 24,
@harmanm had their BG status change from "next step is to conduct a background check" to "background check is in progress" with no "NA" in between:
Yesterday they received PPR and apparently the BG status never changed (to NA or IP2) prior to the application being approved... it stayed at "IP1" the whole time, for a total of 120 days!
So it's possible that our applications will stay in this BG status the whole time without ever cycling through "NA" and "IP2"... and it could stay that way for a
long time. I think the lesson is that you can't always tell what stage your application is at based on the wording of the BG status.