When running the Alert History report, some alerts which are displayed in the Event Console are not displayed in the report's results.
This behavior occurs due to a certain SQL join statement in the report where expected rows in the database do not exist. The root cause as to why these rows are missing is currently unknown.
Since the root cause of this issue is unknown, attached is a modified version of the report which does not include the problematic table / join reference. This report may be imported into a desired reports folder and used as a workaround.