NPCs disappear after some time

Hey there,
so I recently “revived” my old server and something new is happening. Some time (1-3h) after the server starts, all NPCs start to disappear. You can see them far away, but as you come closer they despawn. I don’t have any script preventing NPC spawn or anything. Using server artifact 5890 due to txAdmin.
Has anyone experienced the same issue and knows how to solve it?

~ PC

Seems like a FivePD callout caused this issue.