ofox Shi

Your vendor is correct. For smartcard readers, the smartcard redirection feature is recommended over USB redirection feature, no matter the Agent is VDI desktop or RDSH. Your problem looks like, as Rob pointed out, an example of the KB. You might try the workaround in that KB(by installing CDR during Agent installation on your RDSH) to see if it makes any difference, and in the meantime wait for Rob's further info.