Temporary ZCC Network -8 error during automatic login (downloading config. stage) when working from home

Dear Community,

For quite some time now, (new) users working from home cannot automatically login the ZCC after the initial installation.

However, this is only temporary as The ZCC does login accordingly after clicking continue below the Network error screen.

A PAC file is already active when ZCC is not active through GPO.

At trusted networks we don’t see this behavior as the ZCC logs in automatically and authenticates using ADFS (internally available and externally available). At trusted networks, no FW profile is enforced. Custom flags are set to enforce and retrieve the correct App profile. FW & AV processes are whitelisted.
In the captures made with Wireshark & Packet Capture feature of the ZCC the following error appears:

ERR RegQueryValueEx failed. Error Code: 2, lpValueName: WpadOverride
ERR RegQueryValueEx failed. Error Code: 2, lpValueName: WpadHistory

Turning WPAD override on and I get this error in the ZSATunnel.log while the issue is still the same:

ERR Failed to open service handle.
ERR Loopback Exception is required! Windows8OrGreater: true,

We have a case open with Zscaler Support, but I am curious if anybody recognizes this behavior and could provide any possible solution or insights.

Thanks in advance and happy new year.

Roy