What are the smart list filters/triggers and flow actions for the program that is sending the alert? What do you see when you double click the "Skipped" activity in the campaign results section?
HI Trevor - thanks for response, figured it out though. We had two alerts, one just resulting from an operational program - that was the one that was skipped (as it should have been). Still doesn't explain why the correct alert was never received but that could be Outlook.