Adagio Receivables 9.2A (160226) is a Service Pack to Adagio Receivables 9.2A (150410), it is not an Upgrade. An Upgrade would change the version number (9.2A), not just the release date.
Service Packs fix identified issues in a module. They are all accompanied by a
Release Note which describes to problems that have been fixed.
Programs start behaving differently because something has changed in your data or procedures or software environment.