Yes, it was just after the time storm ended. During it, I stayed locked up on the upper floor of my house. The problem isn’t really that they didn’t despawn, it’s that there were too many of them. There were at least 25 in the same spot. Moreover, they were deep mobs, not surface mobs. I managed to kill all of them afterward, as they never left, even 5 minutes after the screenshot. I was forced to kill them all. With my bronze-tin shield, my iron falx, and my steel hauberk, I managed to defeat them, but it cost me at least 15 bandages and 150 durability from my brand new armor.