Been playing the latest FTB Direwolf20 1.20.1 pack and setup my usual out-off-the-way mob grinding farm which is chunk loaded but when I am back at my base there are no items or experience coming through any of the transfer mods available (enderchests and Tesseracts.

The only way I can get monsters to spawn is by standing next to the dreadful dirt.
Tried both mob_grinding_utils-1.20.1-1.0.3.jar and mob_grinding_utils-1.20.1-1.0.2.jar

Back in 1.19x it worked perfect at any distance as long as chunk loaded.

Same issue in TNP Limitless 7 0.27.0

You can use spectator mode to check on builds that should run in the background as your spectating camera should not load anything that a player would normally cause, this might be a good way of checking to see if something is going wrong with MGU or if something else in the build is not working. A short video would also help a bunch too! :D

I'm not sure if this related to #245
It does sound like a similar issue, and this mod (below) was suggested as a way to circumvent some spawn rules.
https://www.curseforge.com/minecraft/mc-mods/mob-despawn-timers