Large mushrooms require the corner area around them to be empty

How to reproduce

1. Grow a large red mushroom
2. Place blocks in the corners around it, and one block on top of the red mushroom to limit the growth in the next try
3. Remove the large red mushroom
4. Try to grow a large red mushroom in the same place

Also affects the brown mushroom variant. Probably also affects the outside area around the top part of red large mushrooms.