I'm doing the minutemen missions in fallout 4 with hopes of unlocking the final mission. Unfortunately, I'm stuck in a mission where I'm supposed to eliminate raiders at olivia satellite station. I got the mission from Preston and it never activated. I toggle it on, no markings on the map, globally or locally. I nevertheless went there and cleaned the place up, but no luck. Also, it seems to be one of those missions that don't fail by themselves with time.
I'm playing on ps4 so no console in this case. Am I still able to unlock the final mission? What are conditions for unlocking it?