I’ve just had this problem and found that cause was in the world settings of my main (persistent) level.
I’ve used some assets that came with premade level where “Force No Precomputed Lightning” was ticked in World Settings.
As it only had some Landscape and basic lightning I totally missed this setting and was concentrated on my actual sublevels and their content.
So for anyone having this problem - try to build lightning on all used levels one by one while the rest are turned off.
Or just check if “Force No Precomputed Lightning” is ticked for any level you have.
Thanks a lot man! broke my head over this for a couple of days and even made a seperate forum post about this, completely looked over it. now my swarm agent starts properly