We have completed the certificate update on the impacted nodes.
In addition there is another Let's Encyrpt root certificate expiring on 09/30. This is not expected to cause any issues but we are keeping a close vigil to ensure that there is no impact.
Posted Sep 30, 2021 - 02:06 EDT
We identified the issue is due to an expired intermediate certificate of Let's Encrypt which was present in Windows OS and distributed from Microsoft. This did not impact IE or Chrome, but it did impact the monitors that rely on cURL on this OS. This is because cURL uses a different prioritization scheme to select the trust chain for certificate validation. We are working to resolve this on our nodes by removing the offending certificate.
Devices can also encounter this issue if their devices have not downloaded the latest CA certificates from the OS manufacturer. Companies whose customers are impacted should make sure that the latest OS patches have been installed, or reach out to Let’s Encrypt for assistance.
We will update the status once the certificate update has been completed on all impacted nodes.