Is there any way to guarantee the secret keepers spawn after Overthrow? They won't show up fo rme.

Knocked out several different overthrows last night, some in the same zone, some in different zones, but the secret keepers never spawned (I watched videos showing where they spawned, and also ran all over the zone).

I have completed the Ergo Sum quest, and the story, legendary story, and excision. I've completed a pathfinder in the pale heart this week.

I haven't completed all of Micah's quests, I don't think.

I don't yet have legendary or exotic Khostov.

I have not completed the raid.

I've only been trying the solo overthrow, is that a mistake? Do they only show up in the match made activity and you just have to wait for it to rotate around?

Do I have to do all three overthrows, kill all three secret keepers, then unlock and do the exotic mission all in one go? That seems like it's going to take an insane amount of time in a single evening if the secret keepers have a low spawn rate.

On the other hand, if I can just kill secret keepers whenever, and my progress towards unlocking is preserved, I'm fine with a low spawn rate, I'll just keep chugging along and eventually get them all over the course of several days.