Hey there, Thank you for reaching out. We understand you didn't unlock the triumph [i]The Floor is Lava[/i], despite fulfilling its requirements. This does sound strange to us. Should this recur, please consider capturing a short videoclip of the issue. A videoclip which demonstrates your fireteam not getting hit by Protheon's fiery ground attack and completing the Inverted Spire without the triumph recognizing this would be helpful. If you record such a video, you can upload it to a site like Imgur or Youtube, and share a link here. We'll then investigate.