that happens for many reasons. interviews, remedicals, doc requests, etc. are all things that delay apps. they also had a backlog from islamabad VO which im guessing is mostly gone by now. furthermore, not too long ago they would only start background checks after eligibility had passed, but they're now doing both in parallel to reduce processing time.
in the end, only god knows how long they'll take for us December applicants, but there's always a chance that we might be done sooner than we think.