From the wiki: "The density cap is split up into two distinct categories: a cap for surface mobs, and a cap for cave mobs. Cave mobs do not count toward the surface mob cap, and surface mobs do not count toward the cave mob cap". Also, the monster density cap for cave in the overworld is only 8. It means that there can only be 8 monsters in a 9x9 chunk square region around the chunks that can spawn them. That's really low. So even with despawning rules being changed in the betas, we can't get a lot of mobs at once from normal spawning at all.
Felipe Viana
MCPE-78851
It affects the 1.13.0.18 beta as well. Same for 1.14.0.2 beta.
Maybe the issue is the mob density cap?
From the wiki: "The density cap is split up into two distinct categories: a cap for surface mobs, and a cap for cave mobs. Cave mobs do not count toward the surface mob cap, and surface mobs do not count toward the cave mob cap". Also, the monster density cap for cave in the overworld is only 8. It means that there can only be 8 monsters in a 9x9 chunk square region around the chunks that can spawn them. That's really low. So even with despawning rules being changed in the betas, we can't get a lot of mobs at once from normal spawning at all.
Duplicate of
MCPE-41103