Apple actually directs Mac/Bootcamp users to the AMD site as they no longer provide updated drivers with a Bootcamp installation.
The latest drivers (10/06/2020 Unified R4) which includes the for 2017 iMac, breaks Blender from 2.83 to 2.91.
With the new drivers you can no longer select a mesh object with the mouse pointer, in the viewport.
***Reverting to the previous drivers from march resolves the issue.
I know it’s not your area at AMD, but I was hoping @bsavery could do a quick read of this post and give some guidance on who I should report to.
I would say AMD. If you changed a driver, and the previous one works, then the issue is in the driver.
Now you could also file a Blender bug report, knowing that it will most likely end up getting closed, just so it is searchable on the tracker if anyone else has the same issue.
Question: Does the issue occur when using both macOS and Windows?
Random thought @ AMD: it would be nice if there were release notes on the download page for Bootcamp drivers, like there are for other drivers… I downloaded the .zip to check if they are included. They aren’t as far as I can tell.
You should always report issues to the application developers, in this case Blender. They may either figure out they introduced a bug, or understand what needs to be done to reproduce the issue with the driver, such that they can report the issue to AMD.
That’s what I was sorta leaning towards with my original post. I just wasn’t sure if cluttering up the bug tracker with AMD’s issue was no-no or not.
I’ll definitely let the Blender Foundation know.