As I was, you're incorrect about the way that works. (I was just schooled on this, actually)
It'll save the timers for a dynamic zone, but when it shuts down, the spawn states aren't saved. So spawn timers will still work properly and spawn the spawn points that need it, they don't take into account what was there before the zone previously shutdown.
If you want to save spawns, make the zone static. Wish it wasn't that way too
