Omg I am going insane LOL.
I am so close.... but yet weird things keep happening.
After your last message @de0u , I turned the phone back on, and it showed a Google screen, then a Graphene screen! Then it went to a white screen that says The Bootloader is unlocked with a warning message under that... and under that, further down, Welcome to Graphene in big letters... with a blue "next" button at the bottom!
So I restart my computer, I check the Device Manager and the USB driver I downloaded earlier is not at the top like it was when it said Android Device - Android Bootloader Interface. But I just went down to the Pixel on Device Manager to update the driver and it says," the best driver for this device is already installed.. then below that MTP USB Device (I used these instruction - https://www.youtube.com/watch?v=9Wjbte6nnTs)
Moving on, I plug the phone in and Windows says "what do you want to do with this device - pixel 6a" - I exit that... (but think, this is good, it sees my Pixel)
Then I open Chrome and the Graphene install page.... I scroll down to Lock Bootloader .... but it cannot see my phone!!!!
Grrrrr.... I almost want to give up... but it seems like am so close.