This has been going on since version 1.14.30 and still persists into the recent 1.16 update. When I'm out killing naturally spawning mobs, like enderman, zombies etc. after an hour or so spawning completely stops. I can stand in the middle of a feild and AFK on any difficulty and no mobs will spawn. This completely breaks farms, spawners and overall mob hunting game play. Here's world download link: https://www.dropbox.com/s/pnff1weohrbusve/enderman%20nation5.mcworld?dl=0

Update: Happened again today, with several players in a LAN game the spawning just stopped. NOTHING is spawning in the Nether. No piglins, ghasts, hoglins, nothing. This is a game breaking bug.

Update: 6/27/2020 - Issues is still persisting, thought it was tied to another player joining. I've been playing with a friend for a few hours and mobs were spawning for about an hour and out of nowhere no more mobs spawn! Nothing at all! Here's a video link showing that there are no mobs spawning. https://www.youtube.com/watch?v=rkkGxq16Odo There should be mobs everywhere trying to kill me. I have noted that restarting the game SOMETIMES fixes the issue but this kicks all other players out of the LAN/multiplayer game.