Issue on "Insufficient Permissions for Download Folder"

[fertonon]

Hello everyone! I have an annoying issue and I'd like some input on how I could solve it.
I'm getting this message upon starting Keyshot 6 on the Mac. (image attached)

Insufficient permissions for internal downloads folder: [...]
Both user and group requires read/write access permissions. This will yield problems during runtime until it is fixed.

I have searched the web for solutions, and I found this thread https://www.keyshot.com/forum/index.php?topic=10219.0 addressing this very issue.
The thread in question solves this problem by altering folder permissions to read/write to group users. But mine has a twist:

I'm on a Mac but I use SolidWorks to design, so I also use Keyshot on the Bootcamp partition running Windows. On both, my folders are located on Google File Stream, so the folders are the same and downloads/customizations are updated regardless of which system I'm using.

So in Finder the File Stream folders don't have group access permissions, only the user (read/write, fine) and "Everyone" (set to "No Access"). Those are the only two options listed on "Sharing and Permissions" section in Finder.
And Finder absolutely doesn't let me change the status of "Everyone" to "Read/Write".

Any thoughts on how to fix this?

No issues to report on Keyshot running on Windows 10 Pro, and my configs are as follows:
iMac 27" mid-2011
MacOS High Sierra 10.13.6
Keyshot 6.3.23
Google Drive File Stream 26.1.21.2238

Many thanks in advance,

Fernando