When pressing Alt+Tab while on a VDI in ICA session Full Screen, the apps show up from the endpoint and not from the VDI.
Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.
To resolve this issue change the following registry key on the client machine:
32-bit OS:
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Keyboard
Type: REG_SZ
Name: TransparentKeyPassthrough
Value: Remote
64-bit OS:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Keyboard
Type: REG_SZ
Name: TransparentKeyPassthrough
Value: Remote
Transparent key was not passing through.