In my world I went into a cave for a temporary base and closed every hole from above ground and lit it with torches, but I seen multiple times monsters fall through solid blocks, but its not just anywhere it's a certain block, and its really annoying and a little scary because a creeper almost took me by surprise, and I seen it happen for skeletons. Just saying this is in a jungle biome, so maybe the vines underground are glitching to get the monsters to go down through blocks because of vines. Please fix this.