The core parking issue reminds me of a problem I had back when I first got a Ryzen 7 3700X.
I installed the AMD Ryzen Master utility to mess around with the OC profiles, and then uninstalled it. From that point forward, the CPU was stuck in some kind of "Eco" mode and would not go over it's base clock. It would override my BIOS settings. The only way to get the CPU to perform normally was to reinstall the AMD master Utility and run it at all times with the standard profile. It had to be reset every time I booted the PC, and any time the Master utility was not running, the CPU would revert back to this eco mode. No amount of installs/uninstalls of the drivers/utility could get the CPU to go back to normal. If this was caused by some kind of change in the registry, I couldn't find it nor could I find any way to revert it.
I still have no idea what the utility did to the OS to break it in this way.
The only 2 solutions that could fix it was to create a new Windows profile, or to reinstall windows.
Since then, I refuse to install AMD Ryzen Master on any of my PCs.
So if the problem is related, maybe making and deleting a bunch of new Windows profiles will be faster for testing CPUs than reinstalling the OS over and over.