Flawless Execution Bugged

So I have been trying to get the Flawless Execution 2 challenge 10 missions on Malice without going down for the Steam achievement and its bugged.

I have completed 12 missions in a row but it only counts if the mission starts from the beginning. If I join a match after it has begun it counts as a down and I have to start all over again.

This is not good enough. If you add achievements and penances then make sure the work properly please.

My progress is stuck on 14/15