My final weekly challenge is as simple as it gets and its "complete 5 fiesta matches. The progression stopped half way through with only 3/5 games completed. Ive done all 5 to make sure. This its not so thrilling to play a game mode that has a bad algorithm that spawns poor weapon combos with you fightinh a tram that consistsntly get top tiered weapons.
Of course 343 continues to screw up their challenges. Apparently you need to WIN 5 Fiesta games not just complete them.