can not craft bamboo planks with 4 bamboo items

This is intended behavior as described in the snapshot's article:

https://www.minecraft.net/en-us/article/minecraft-snapshot-22w45a

• Added Block of Bamboo and Stripped Block of Bamboo

  • Block of Bamboo can be crafted from 9 Bamboo and can be stripped like other wood logs

  • Bamboo Planks crafted from Block of Bamboo yield only 2 planks compared to 4 for wood logs