A red triangle is related to the revenue driver. It highlights that for a specific segment, PMI does not have enough seasons or historical data to calculate the revenue driver.

In this case, PMI looks at the last 50 days to give a suggestion.  If you have a new segment, PMI will sometimes not be able to make a suggestion because it does not have enough historical data. On days with a red triangle, you should have a closer look and manually edit the pickup, if needed.