Hey Cronicshift, Ive had the same issue. What fixed it for me was killing absolutely everything around koftiks and then when you get koftik’s health all the way down and it goes into that exploding glitching animation keep shooting and you will still get damage numbers. It took me two or three runs before I did this and it worked first try. I have also seen people put the already collected motes in the vault, but that was not necessary for me. Good luck let me know if this works!!