After setting up a QAS server, the vas.conf settings change.
The VAS Configuration settings in Group Policy can apply single line edits to the vas.conf. Any VAS Configuration setting in AD will add or overwrite that particular line in vas.conf, but any settings left empty will have no effect. This allows any vas.conf to be a combination of locally set parameters and centrally managed parameters.
To see what changes are being applied to vas.conf by Group Policy, run the following command as root on a joined server and look at what it says about "Modifying vas.conf settings" :
Any settings that should not be applied should be cleared in the VAS Configuration object in Group Policy, which is Computer Configuration | Unix Settings | Quest Authentication Services | VAS Configuration. Note that when a setting is cleared in the GPO, it is removed from the vas.conf, so you may have to set it back to whatever it was before the Group Policy was applied.