Hello,
It is possible that the Raphsody output automatically passed to the clipboard and then it went to the NoMachine client. This is needed to automate the process of copy-and-paste text from the remote session to the client host.
If you don’t need such feature, you could try editing the file /usr/NX/etc/server.cfg to add the line:
EnableClipboard none
This would disable the transmission of clipboard content to the client host, so it should work around the problem.