I made ilmango’s mob farm tower in a self created void world. I had to make a void world due to the 128 block vertical rule being ignored. I created 9 spawning platforms with the top two being slabs and the bottom seven being cobblestone. Mobs never spawn on the top two layers. I even flooded the bottom seven and I might get one spawn in several minutes.
https://bugs.mojang.com/browse/MCPE-28587 this report might also be affected by slabs although overall spawn rates do not seem as prolific as on java edition.
Linked issues
relates to
Comments
migrated
[Mojang] Mega_Spud (Jay)
Cleaning up old tickets: This ticket has not been updated recently (~1 year+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.
Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki
I can confirm this (was going to file my own ticket before I found this one).
In my case, I built the tower in my single player survival world before the latest update, with every platform being made out of top slabs. It worked extremely well.
After the update, not a single mob will spawn on it.