I've been looking for a while now for a solution to this, but can't figure out exactly what's going on with this issue.
I bought an unlocked Pixel 8A. Trying to install GrapheneOS on it. Signed into my Google account on the new 8A, did a check and installed all current updates on the phone. Can unlock developer mode with no issues, and I can toggle the "OEM unlocking" setting without issue. But when I boot up the bootloader interface on the phone, and attempt to unlock the bootloader using the web installer, my phone shows up as a device I can connect to, but I immediately get the error "Error: Bootloader was not unlocked, please try again!".
On the phone, I also see that it lists "oem_locked" in the text on the bootloader screen. From what I understand the web installer has to send a request to the phone to unlock the bootloader, which has to then be acknowledged on the phone itself, but I never get an option on the phone to do that.
I've found several posts saying that their device was still OEM locked even though they purchased an "unlocked" device, but I don't think that's the issue for me since the toggle for "OEM unlock" in the phone settings can be toggled on and off (not grayed out).
I'm using a Windows 11 laptop, running the Web Installer using Chrome.