ePO uses TLS to secure the communication between ePO and several of our back-end servers. The original root certificate from the public CA that we derived our certificates from expired on May 30, 2020. A new root certificate, which won't expire until 2038, has been in place for several years. But, if you've turned off Automatic Root Certificate Updates on your ePO server, you might be missing the new root certificate. As a result, some components of ePO or some ePO-product integrations aren't working properly.
Any connection ePO makes that requires TLS has the potential to be impacted. These connections include connections to third-party servers if they're signed by the same expired root certificate. ePO's core functionality isn't affected. For example, agent-to-server communication doesn't fail because ePO acts as its own certificate authority. ePO's Master Repository pull also doesn't fail because it doesn't use TLS.
For additional information not-specific to ePO regarding this, see
KB92937 - Secondary root certificate for TLS might need to be updated.
The problem statements below provide details about the features of ePO confirmed to be impacted by this issue.