OK. Before I tried Brian's 4:36pm reply I decided to try one other thing.
Hard Drive Config for this test:
SATA SSD - Unhooked
NVME SSD - Up and running
What if I installed a clean copy of Windows 10 onto the NVME and then tried copying those partitions and adding boot items for them.
Then try seeing if same behavior of the bios changing the boot manager.
And to my surprise, it actually worked. I have 6 partitions now on the NVME.
I have these Partitions:
GROUP 1- 1 clean NVME W10 install. 3 copys of that same clean install. All have boot menu items in BIU.
GROUP 2- 2 partitions from my original SATA SSD.
I have no problem now bouncing around on GROUP 1 menu items in BIU. It works like expected! I'm happy.
But whenever I click on a GROUP 2 menu item, that's when the BIOS boot manager changes.
So, at this point I've just reinstalled everything onto one of the cleans copies. It was a bit of pain, but at least everything is fresh now.
I have my data of separate drives. So my data wasn't affected.
So really at this point, the only question left is what is in those original SATA SSD partitions that takes over the BIOS? It's kinda of a bummer I couldn't have just quickly gotten this to work with my old backups. But I'm glad now that I can get back to my PC working the way it's used to.
Thanks for the help guys, especially Brian K
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