This is a fairly major bug, someone else reported it on September 9th. Creatures no longer despawn based on a range.
Please select what you are reporting on: UEFN & Creative 1.0 & 2.0 Devices.
What Type of Bug are you experiencing?
Creatures / Creature Manager Device Issue
Summary
Despawn Range from PLAYER or from SPAWNER no longer despawns creatures (zombies) on the Creature Spawner Device. You can run as far away as possible, and the creatures will remain in the map. This causes major issues for maps that rely on despawn of zombies.
Steps to Reproduce
Place a Creature Spawner Device and put any despawn settings on it. For easy reproduction set the despawn range to player, or spawner, and make the range small. Run away from the spawner or creatures and they do not despawn.
Expected Result
The creatures despawn based on your range from them or their range from the spawner.