Instant De-spawning of Mobs when Player not nearby

[Bifasaurus]

Modpack

FTB Presents Direwolf20 1.20

Modpack version

1.12.1

Log Files

No response

Describe the bug

When mobs spawn in a force loaded chunk without a player within 3 chunks they instantly despawn. See the attached video taken using an Ars Nouveau Scyring lens to view the far away (~100 chunks) mob grinding room remotely. Mobs are being spawned in a hyperbox at my base and then teleported to the grinder using the wormhole mod portal.

720p.Insta.Despawn.of.Mobs.when.Player.not.nearby.mp4

Steps to reproduce

1. place apotheosis mob grinder in a force loaded chunk
2. modify the spawner so it runs without a player near by and under all conditions present (light etc)
3. Move 4 blocks away and check if mob are spawning via map.. Also, see that the running mob grinder is not adding new drops to inventory system.

Expected behaviour

Mobs to be spawned and ground in mob grinder remote from base

Screenshots

see the attached video of mobs being teleported to the mob grinder from a hyper box and they instantly de-spawning because a player is not nearby.

Additional information

Seems like an anti-lag program of some type is causing this...any ideas?