Without knowing more details its hard to say. Usually aor is just to check that all documents are provided and complete. It could be verifying record of landing, brief check of days to qualify. Did you have additional security check during PR, visa of another country rejected or something of that sort?Can anyone explain what further review below could mean?
If you still haven’t received your AOR, your application may be
Submitted my wife's application online on the 19th and still haven't received AOR. She is traveling indefinitely on the 16th and we really wanted the peace of mind from AOR before she left.
- incomplete and on its way back to you, or
- going through further review before we start processing it