So I had a recent epiphany on how Slim’s Spore Cloud objective for the second star which is to keep the Monster in a Spore Cloud for 20 seconds 20 times. I’ve heard people say that it’s bugged and that they’ve tried doing it with their friends in a custom with no progress. Me and my friends have found out what the problem is. You can keep shooting Spore Clouds non-stop and it still counts as one Spore Cloud if they’re connected and there’s the problem. The timer for the single cloud continues as long as they’re in that cloud. This means that if you keep the Monster in a Spore Cloud for 60 seconds it only counts as one. So basically you need to “refresh” the timer so to speak to earn another point towards the objective.
TL;DR The Spore Cloud second star objective only counts once per area meaning the effects have to wear off on the Monster for another timer, for another point, to start. Basically once the Monster has been in a Cloud for 20+ seconds let it wear off.