flashing a custom ROM that was intended for a particular device into another, is a guaranteed way of breaking that device.
I wasn't talking about that at all. I just refered specifically about unlocking the bootloader. I know you have to find a specific ROM for every specific device.
So weird I cannot find one though. I bought the G22 because it just seemed the most affordable alternative to a Fairphone (i.e. you can change the battery and the screen if something happens, or the fingerprint sensor/lock button etc.).
On XDA there is not even a section for it.
Also Nokia is owned by Microsoft
No, they're not any longer. Since a few years already. They gave up their rights to the brand after their phone projects flopped.