I’m on PS4 myself, it’s not trophies, it’s more the missions themselves.
It must be an account-issue or something like that. Few days ago I completed all challenges on every Sniper Map, and also reached mastery level 20 on every map. I played 40-50 times on every map, and had never a bug or any problems. (PS4)
That’s what I assume. It’s only the one map for me, never the other two. I have just challenge left on that one map too and it’s annoying that I can’t officially clear it.
I never had problems, after completing a sniper mission.
I mentioned this in bug report but, the mission I have trouble with doesn’t allow me to load the leader board at all, I think the error is actually due to the leader board and not the mission or accounts themselves.
Issue is resolved now. Completing any of the Sniper mission does not get you disconnected. Previously completed challenges also show and are reflected. Sniper upgrades are also unlocked.