How do you reset Act4 Niko quest?

My quest is bugged out and it just keeps spamming me with "talk to niko" or "Collect Voltaxic Sulphite for Niko" in any zone including my hideout. I have done his later map quest just fine but the A4 quest is uncompletable. I've tried running through the mines a few times hoping some sulphite would spawn but no luck.

So is there a way to reset it?

I'm in the same boat... PM me if you have found a fix for this!