They are different kinds of unlocked! Unlocked generally just means "can be used with any carrier". For example this Samsung S22 I am on is "unlocked".
But Samsung hasn't allowed unlocking the bootloader on their phones for many years. And they are far far from the only ones in that state.
You basically have to research each specific phone far ahead of time. And beware! Because there's, for example, lots of guides telling you how to unlock my S22 phone. But as of ~2023 Samsung now blocks all those previous exploits that the unlocked software used to use.
It's a mess and a half.
Eesh, that does sound rough. The last Samsung phone I owned was the Galaxy S5, I see on the Wikipedia page Samsung devices have been locked down since early 2021 :(
Not like I would try to give you advice on unlocking your phone in the first place as I'm mostly clueless myself.
Maybe time to trade up or sideways? Graphene OS only officially supports Google Pixel devices anyway(for now). If Motorola could somehow recapture the magic of the Razer today with a new phone, that would be cool too!
https://grapheneos.org/faq#supported-devices