The reason that this certificate authority integration test connection failed is that fetching the root certificate from CA failed. The root certificate from CA is a certificate that validates the identity and trustworthiness of the certificate authority (CA) that issues certificates for devices. Workspace ONE UEM needs to fetch the root certificate from CA to verify and manage certificates for devices. If fetching the root certificate from CA failed, it could indicate that there is a problem with CA configuration, connectivity, or availability. Workspace ONE UEM will not be able to connect to CA or issue certificates for devices, and the certificate authority integration test connection will fail.