The disconnect option in the GlobalProtect client is greyed out and the client cannot be disabled.
Resolution
Go to Network > GlobalProtect > Portal > "name of portal" > Agent > "name of agent configuration" > App and check the following settings.
1. Is the Connect Method set to On-demand option (Manual user initiated)? The disconnect option will be greyed out/not available the Connect Method is set to On-demand. In On-demand mode, the user has the ability to connect and disconnect whenever required.
2. Is Allow user to disconnect GlobalProtect App (Always-on mode) set to Disallow? In order for the disconnection option to work with an always-on connection method one of these options must be used, Allow, Allow with Comment, Allow with Passcode, or Allow with Ticket.
3. Is Use Single Sign-on (Windows) or Use Single Sign-on(macOS) set to No? To allow the GlobalProtect client to disconnect Single-Sign-on should be set to No.
Additional Information
Additional information for, Connect Method, Allow User to Disable GlobalProtect App, and Use Single Sign-on ( Windows) can be found in GlobalProtect Portals Agent App Tab.