I'm not sure if this is a placebo effect or some kind of red-herring I've stumbled upon, but as of the last two days, I've noticed (mostly in Inferno while grinding prestige) that the presence of Tyrannocytes (Tyranid drop pod things) might determine if the game will crash or freeze at the end of an Operation.

To test this, I ran 6 of Inferno on my Series S and organized them into two categories: those where the Operation had previously triggered a Tyrannocyte landing in the map and those that did not.

Of the 6 operations I ran, three had previously triggered a Tyrannocyte in the map (most frequently during the generator defense) and three had not.

Of the three that had crashed, 3/3 (100%) of them had a Tyrannocyte on the map.

I'm still not entirely sure if this is actually a cause of the crashes - could just be luck or random chance causing the crashes - but I think this could be one of the causes behind the crashes plaguing the Series S since the game's release.

If anyone else can confirm or deny if operations where Tyrannocytes are present / have triggered in the map suffer more crashes than if they haven't, please leave them in the comments.