A Lot Extra Achievment

I know that there is a thread about achievement problems, but it doesn’t seem to get anymore attention. In my campaign menu I have all the objectives completed for ever mission. On halo waypoint I have 64/65 sub objectives completed but on the mission a new enemy I have 7/8 sub objectives completed and there are only 7 sub objectives in the game. According to other people the achievement should unlock for me. However the achievement is still listed as being 88% completed. Is there anyway to fix this?

Creating a new thread isn’t really going to help solve anything any faster, please log any achievement issues in the dedicated thread thanks