When Kerberos cache is managed by KCM, tickets cannot be delegate inside the NoMachine session.

As a workaround, configure the Kerberos setup to use a different type of cache, for example FILE type cache.

For example, to do that on RHEL/CentOS systems, edit the /etc/sssd/sssd.conf file and add the following setting, after 'krb5_realm':

krb5_ccname_template = FILE:/tmp/krb5cc_%U_XXXXXX

Then, restart the SSSD service:

systemctl restart sssd