Having An Issue With Assassination Phase Of Low?

[(XBOX)Darth Killzn]

I've been with two parties now where we got through the first two parts smoothly and on the third we run into an issue with the furnace doors. No matter how we stand on the pads, jump of and back on same time , stand on all the pads at once, nothing worked. Eventually we spent so much time that people started leaving and hope was lost lol. I'll try to see if there are any other threads in the meantime covering this because I haven't yet.