The blocks "Bamboo Mosaic Slab", and "Bamboo Mosaic Stairs" are not in the #slabs and #stairs block and item tags. This is because they were originally in the #wooden_slabs and #wooden_stairs block and item tags, which are included in the #slabs and #stairs tags. However, they were later removed from these tags, and were not then put directly in the #slabs and #stairs tags.