Good day,
sorry to tell you, but this doesn’t seem to be a problem created by Whonix, seeing how one RD can be accessed, while the other one can’t, which is why it will be hard to help you on that.
Regarding the error you got, maybe this can help you: SSL_Read: Failure in SSL library (protocol error?) on Win2k8 hosts · Issue #733 · FreeRDP/FreeRDP · GitHub
Have a nice day,
Ego