here is my experience with the same problem.
Manjaro linux installed on a Lenovo T470, I followed the web install method instructions exactly using chromium and the USB-C cable given with the pixel 6a.
I encountered the errors "unable to claim interface" or an error to transfer out/in via USB (tried more times), when the smartphone was rebooted to fastbootd.
Then I tried with the same setup via CLI using fastboot from the distro and the one downloaded, and had the same problem with a different error message. I used the following grapheneos releases: 20221018, 20221016 and 20221015
Then I tried to install android 13 from the google website and it worked!! I was puzzled...
Then I took another cable, USB-A to USB-C from Anker, and put it in a different port and the web installer didn't work. Then I tried via CLI and it worked perfectly!!!
I'm even more puzzled then before, but very happy at the same time! :D