Finally decided to give GrapheneOS a try as I've got a fp6 with /e/os and love it.
Found an eBay listing for one in very good condition, and right in the subject it says unlocked. Got it yesterday, excited to try it. Start following the install instructions, only to see OEM unlock grayed out. One article says, it must be connected to the internet, so I connect it to wifi. Still grayed out. Another article says install all the updates and reboot. Two hours later, still grayed out. I've measaged the seller asking for a refund, but I don't know. Anyone else have an idea?
So like @UnpledgedCatnapTipper@piefed.blahaj.zone found out it's a Verizon sold phone and Verizon are absolute fuckwads about letting you unlock the BL.
When the seller said "Unlocked" they meant carrier unlocked as in it will accept any non-Verizon SIM card
Now, generally, for every other US carrier that does also mean you have the ability to unlock the BL because per Google policy when the phone is carrier unlocked then you will be able to BL unlock...
...except when that carrier is Verizon
Not sure how successful you'll be on getting a refund, because technically they didn't mistake anything the commonly accepted definition for "Unlocked" in this context is carrier unlocked. Which you would have been fine with, again, had that carrier not been Verizon.
Fuck Verizon.