Upon completing a stopwatch game mode, the final experience (Game, Support, Combat) is not being correctly applied to the mission values. i.e. In a across the two rounds of a stopwatch game, you may earn 3,300 Game Mode EXP, however the total experience towards a mission might only slightly increment instead of being roughly half complete (assuming the 7,700 goal). This bug does not exist in Objective mode.
If I had to guess, it is only applying the experience from the second round to the mission totals, instead of the entire amount across both rounds.