PocketMine-MP Server not able to place crystals

I have started a Minecraft Bedrock Server with PocketMine-MP.
I can place/break other blocks, but the end crystal doesn’t appear in the Creative Inventory, and if I give myself the crystals using commands, when I place it down, it disappears, and I cannot break it, so it’s not invisible. Trying to make a CrystalPvP server; please help.

Edit: Also, I’m placing it on Obsidian.