Free for all challenges are broken

Title says it, i have 2 free for all challenges, neither last spartan standing and rumble pit contribute to the challenge. The only other thing i can think of it is that it only works in FFA and not rumble pit but thats not an available playlist and i dont want to use challenge swaps.

That being said im having alot of fun with season 2 so far. Last spartant standing is crazy fun and i won my first two matches. I also played swords and grapple hooks only and that was fun too.