I am dealing with this same issue. I believe this is due to the fact that the alerts are based on Performance Rules and are not Monitors and there is no defined rule that tells SCOM when to auto resolve the alert. I am still digging to see if something can be done. Personally I would like to configure the alert to run multiple samples, or average the utilization over a set time before alerting.
I have what may be a simple question. I have intergrated the Orion Management pack vs 1.1.1 and before I set this override as descirbed I am seeing a lot of "notification" alerts that seem to be based on the "warning" alerts that Orion sends. If I set the override you described will this effect "critical" alerts from Orion? Just trying to understand before I silence something that could be useful.
You both seem to be trending ahead of my next questions with what you have posted so forgive me if I am dragging you back just need a little insight from someone who is ahead of me on the SCOM integration.
Thanks in advance....