Hi Britgirl,
I can confirm that I have got this working!
My mistake was commenting out
auth include su
in /etc/pam.d/nx.
Connecting to my cloud server gateway running CentOS9 stream using the NX protocol now correctly prompts me first for my LDAP credentials, then for my RSA SecurID authentication code.
Thanks for your help. Once you’ve tested this yourself you can update your 2FA documentation at https://kb.nomachine.com/AR12L00828#3.3. as it doesn’t currently include theNX protocol.
Cheers.