Items and blocks added into 1.17 don't register in-game.

 I am attempting to create an addon for Minecraft Bedrock Edition, but none of the items or blocks added into the game actually register. All experimental settings are turned on, and both the resource pack and the behavior back are applied. The format version is set to 1.17, but this still doesn't work when I set it to 1.16.220. The block is formatted correctly and the texture is registered.