If you enter a location and start a tactical mission and then reload the autosave, you will find that the Number of Missions of all agents have increased by one, even though the autosave is from before the mission started.
The counter for agent number of missions should increase only when the agents have loaded into the tactical gamemode. For someone like me that likes statistics, it greatly bothers me that the mission counter for every agent can be off by ten missions or more towards the end of the game.
Usually it’s something like me loading and taking all the paralysis pistols and paralysis melee weapons off my agents versus the Pure in hindsight, or realizing that my agents aren’t carrying their sidearm weapons because I had just come from a loot box mission.
Or it could be something like the game not allowing me to fine tune my agent loadouts, but without telling me such as The Gift mission. And I may have wanted to spend XP and assign mission-specific weapons for that map.
In all it’s an annoyance and I find that I have to make manual saves before each fight in order to have a restore point, and forgetting to make those saves makes me want to abandon the game when the mission counter gets updated erroneously.