When you start a VDA 7.6.300 or later, you see all the policies applied to it under the registry : HKLM\Software\Policies\Citrix. But, when you run a GPUpdate /Force, or wait for next GPO refresh, these settings are removed from the registry. 

This is a known issue and has been taken care by a bug fix. Call Citrix Technical Support and ask for bug fix LC5204. The same is being tested at the moment to be a part of next major product release.

Problem Cause

When we launch an ICA session, Citrix code will directly start the CSE engine. Then the engine obtains GPOs from Active Directory via an API, so it’s understandable that all settings in GPOs will be applied. Things are still the same if we don't enable GPO caching, even with LC1987 in place. But if CSE engine is started by gpupdate, things are a bit different when LC1987 is in place, now we change to rely on the parameter(pChangedGPOList) of CSE entry procedure to obtain the GPOs, by doing this we don’t need to explicitly call MS APIs anymore. This is where the policy processing is seeing a short circuit.