Three weeks and you haven’t re masterworked it yet? I did mine back up the first day I went to put it on.
You think they are going to do it for you?
They probably know why it happened, but I find it funny that is the only gun I heard about with this issue.
Just level it up and move on. Even if it’s your last cores you’ll get more.
If it was still a blast radius masterwork, sure. If I knew that blast radius MW was no longer an option on it, sure. However, that's not the case. It's no longer what I consider to be a god roll, so it's not worth blowing through 1/10th of my cores to upgrade it again. I don't care about losing the kill-tracking. This isn't my Sunshot with 4k kills on it, it's just my PvP only GL with 300 total kills.
If Bungie introduces a bug, you better believe that I expect them to fix it. I've moved on from the gun itself, but it's the principle of the matter.