ICES is the CBSA database I was referring to which has the entry/exit records and IRCC validates the same. It stands for Integrated Customs Enforcement System. Balancing of probabilities means IRCC was not able to verify/validate all travel records so it looks like they approved your application as it was more than 50% probable.
"Findings of fact, as well as determinations as to whether the applicant's evidence is credible, are made on a balance of probabilities that is greater than 50% or more likely than not."
From what I understand, AOR is issued after basis completeness check, though exhaustive checks happen in later stages for everything else including Physical Presence. So you will have to wait patiently for AOR, or alternatively withdraw the application and resubmit a new one as you have accumulated additional PP days now.
This is not a legal advice, you can connect to an Immigration lawyer to get advice.
