xTSH

Hi, So i was playing Halo The master chief collection trying to get good times on Halo 2 levels for the Monopolized achievement. I was doing the level metropolis and after hours trying I got under 10mins, but on Halowaypoint it says 1hour40mins+. Why? I would contact 343i direct but they seems to be impossible. Also i was only using x1.00 multiplier skulls which DOESN'T void the speedrun time, to prove this i even got the par score achievement at the same time which would of been impossible to get if I used any invalid skulls and more importantly if i finished the mission in over 1hour40mins. Also i only saved and quit then resumed once halfway through the mission which is normally fine. Is there any way to fix it to my proper time? As i'm sure you can see my frustration of playing the same level for hours and when i finally get a good time it says I've done it in a ridiculously long time. Thanks.