HW 2 Statistics mixed up

Hello! I own the Ultimate Edition with the physical disc and play the game on my Xbox One Elite. I have Downloaded and installed all DLCs except for Awakening the Nightmare.
Comparing my Waypoint campaign stats with my ingame campaign stats I noticed that they are not synchronized properly.
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It’s an issue that needs more clarification. The game shows you:
1. highest medal achieved
2. achieved objectives
3. fastest time
4. highest difficulty
5. highest score (Waypoint only)
Normally, I would say these stats are to be separated for each difficulty one has played. Now, you have no option to switch between Easy, Normal, Heroic or Legendary from the beginn with to check your stats like in Halo Wars / Halo Wars DE which is sad because it gave you a great overview.
In Halo Wars 2 you don’t know what’s going on. Highest Medal? What exactly does that mean? So if I’ve gained Gold on Easy difficulty at Operation Spearbreaker will it still tell me I’ve earned Gold though I’ve played on Normal and only earned a Silver Medal afterwards?
Well, this is the exact problem I’ve got right now. Xbox is showing me I earned silver playing on Normal while Waypoint is telling me I’ve earned Gold on Normal. Plus, Waypoint ain’t showing any objectives at all for the DLC missions although they are present.
The next thing is, I’ve only earned Silver in mission 2 + 3 + 8 + 9 + 10 + 11 on Normal. Waypoint is now showing me this correctly but the game itself on my Xbox isn’t. Here it still tells me I’ve earned Gold from the Easy difficulty I’ve played previously.
The stats are all totally mixed up! If at least one them showed me reliable stats (Waypoint or the game) but the thing is they’re both broken.
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It’s not even fun to play anymore if that’s the way it is.