Sometimes, resetting masterworks doesn’t actually do anything. It appears to reset, but if you then masterwork the item, you will end up with the exact same results. You can tell if this is the case before reworking by starting the game again, and you will find that your supposedly reset item has its masterwork back again.
Of course, you lose all your gold and mats that you spent resetting it, only to have the masterworks back again. I’ve reset this particular amulet 3 times already, so lost a lot of gold in the process. And it still won’t reset.
Video:
https://youtu.be/L-RQcejnpqo