Users can place CustomBlocks in GM2 (Adventure)

Environment: Paper 1.21.8 MythicMobs Latest up to (12/09/2025) MythicCrucible Latest up to (12/09/2025)

Issue description: Users can place blocks created with CustomBlock mechanic in the world even being in Adventure mod.

Code of block:

CrateBox:
  Id: BARREL
  Display: '<color:#ffffff>Crate Box'
  Generation: block/decorations/crate_box
  Model: 40
  ItemUpdater:
    Version: 1
  Recipes:
    1:
      Type: SHAPED
      Amount: 1
      Ingredients:
        - OAK_PLANKS | OAK_PLANKS | OAK_PLANKS
        - OAK_PLANKS | BARREL | OAK_PLANKS
        - OAK_PLANKS | OAK_PLANKS | OAK_PLANKS
  Type: BLOCK
  CustomBlock:
    Type: MUSHROOM_BLOCK
    Id: 40
    Texture: block/decorations/crate_box
    Hardness: 1
    Tools:
      - wooden_axe 1
    Drops:
      - CrateBox 1
  CustomBlockSkills:
    - sound{s=block.oak_log.place} @self ~onBlockPlace
    - sound{s=block.oak_log.break} @self ~onBlockBreak

At screenshot you can see that im using custom block based of mushroom, and it just placed to world. [Legacy attachment omitted]