We've noticed the Windows Event Log Monitor component detecting event logs that don't exist following the upgrade from 6.2.3 to 6.2.4. Example: It detects event ID 123 in the application logs for server xyz and goes into a down state, except event ID 123 doesn't actually exist anywhere in the application logs for server xyz.
This happens across multiple application templates and multiple monitored nodes that have existed and worked normally for years. It has also happened across multiple separate SAM environments within our environment following the same upgrade path. I opened a ticket this morning and stumped two different support folks. They're evaluating diagnostic logs now. We're holding off on upgrading our remaining SAM environments. Just throwing this out there in case anyone else has encountered the same issue.