Trusted CA, Signed Certs and Verification

Hello, I have been trying to use a Trusted CA to sign our freeradius server. The certificates are installed, the key, cert, the root chain all in their appropriate PEM files. The devices try to get the certificate that we specify; However, whenever we try to connect with an iOS device or Windows we get an error saying that the identity cannot be verified. I spoke with our SSL provider's support department, and they say this is normal behavior. There will always be a warning about identity not being able to be verified. Is this true? Am I missing something obvious? Sam Fakhreddine Site Systems Administrator