I just had a phone that failed to allow OEM unlocking from my favorite seller Sellworld, NJ after 3 dozen + phones, but they accepted a return thankfully, they have been very good to me. Just had to return one that the screen was unresponsive and they took good care of me. If you're looking for good fully unlocked phones, they have done me well.
It's a bit tricky to discern the difference from 'Carrier Unlocked' vs 'Bootloader is unlockable' which is the magic phrase. Good luck on your unlocking endeavors!
Goat