While advance alerting of upcoming SSL cert expiration is useful, keeping the check in an excessive down state is not. This otherwise suppresses uptime monitoring, which obviously is a problem. Rather than customers having to add a separate check for just the advance warning (SolarWinds' online guidance as referenced below), it would be far more helpful for Pingdom to send a notification - independent of uptime monitoring.
https://documentation.solarwinds.com/en/success_center/pingdom/content/topics/certificate-monitoring-in-uptime-checks.htm
Since the check will be marked as down from this day until the certificate expiring date once again exceeds the given number of days no other types of issues will be detected during this time, we recommend setting up a separate check for the purposes of expiring monitoring.