Where to find the Download Reauthenticate comments history in Control Builder M Professional
The download attempts are saved as audit events in System 800xA.
Category is AuditEvent_ConfigurationChange and included by the Common Audit List filter object. Default capacity is 10.000 (can be increased to 50.000 in base system) or up to 12.000.000 by IM (+perpetual archiving).
However, I can not see the comment field being saved. Not even in most recent 5.1 (FP4 RevE). Probably a bug. Have it reported to your regional ABB support center.