It looks like the same bug that had been afflicting Stopwatch before:
Only the Game-mode/Combat/Support XP earned in the last played heat/round is counted for mission progress, instead of the full Game-mode/Combat/Support XP earned throughout the match
Bump.
I agree. I also found it really weird that my missions are going very, very slow…and I played only Execution since I noticed that.
It’s been that way since quite a while. I was hoping they’d have fixed it by now.
Since @MissMurder is away at TwitchCon, I highly doubt some dev will notice this 
Hello everyone thank you for your report I will look into this as soon as possible.