For a comprehensive list of other examples of issues with item positions in the Creative inventory, click here.

All tickets associated with item placement in the Creative inventory are valid for cases introduced in 1.16 and later as per this comment. Exceptions exist, which are valid for their own reasons.

The bug

The spore blossom, despite being a flower, functions very differently from all other blocks called flowers. For example, most flowers are x-shaped and require a supporting block below, whereas spore blossoms are concave and require a supporting block above. Despite this, the spore blossom is placed right in the middle of a row of x-shaped traditional flowers in the Creative inventory.

How to reproduce

1. Open the Creative inventory
2. Locate Spore Blossom in Decoration Blocks
3. Locate Lily of the Valley in Decoration Blocks
4. Locate Cornflower in Decoration Blocks
5. Note that there is a considerable difference between these items