I notice many people with issues use setting up a new user as a work-around.

The link in your post for Troubleshooting TT Desktop Issues mentions making sure only one user on the PC is set up to use TT.

Perhaps the Install instructions with the software download instructions should include all these steps up front before your users get frustrated with the install?

Your post is the first I heard to temporarily turn off all anti-virus firewall or other protection software.

I am using Windows 11, it is not the issue.  I have the desktop TT ... not premier, just the $70 version.  I made mine work by setting up exceptions for TT in my protection software, Bittdefender.  It would have been way easier with upfront install/activate instructions to Temporarily turn off or pause my protection software.