I played advent of ascension ,divine rpg,HEE,lycanites mobs,arcana rpg,mo creatures ,rare monsters mod,lava monster,natura and biome o plenty mod and i don't have any issues
Open to on and a switch on cheats. Then do gamerule spawnradius. Then set it to what you prefer. That should do the trick or gamerule domobspawning false but I don't recommend it.