Today I did all the necessary steps to get the Icebreaker catalysts. Everyone else in my fireteam except myself got the catalyst. We all did the steps together and they were able to open the chest whereas I was not. The steps to get there are very long as it is and when issues like this occur it is VERY frustrating. EDIT: I managed to "fix" the issue by completing the dungeon on the character and then rerunning it again and also claiming the triumphs I needed to. Not 100% sure what the exact issue is but it is here for those who may need a solution.