After getting the 3 more AI Cores I needed, I came back and saw that tie ability to research it is no longer there. Does this have some conflict with another type of mod or something, maybe?

Inbetween the time of me getting the mod and then returning with the Cores, the research vanished with nothing new unlocked. I restarted the game a few times during the journey as prolonged play and long-distance travel seems to degrade preformance until a restart. Otherwise nothing else changed. I can still see the 'Space Marine' tab, but there's nothing in it.