Thanks for clarifying that. So I did everything right for these installations. Phew.
Now I just need to figure out why the items I mentioned in my first message refuse to “talk” to my Pixel, even though they work fine with my Samsung.
These items are currently preventing me from switching 100% to my Pixel. Once again, I know that it's not yet officially stable on the Pixel 10 series, so I can run tests if a programmer asks me to.
I really want to find a solution to make these devices work. As I'm new to GrapheneOS, I don't yet have a good enough grasp of the details to be able to fine-tune these settings on my own. I didn't expect to encounter this type of problem with Bluetooth.