Weird spawn egg item dropped when destroying block that has nether sprouts on top

I was building a little nether hut with all the new blocks added to the game and I accidentally broke a nether nylium that had a nether sprout on it. The result was weird...
What I expected to happen was...:
When I destroyed the block, I thought it would give me a nether sprout.
What actually happened was...:
I got a weird white and brown spawn egg with no name attached to it.
Steps to reproduce:
1. Put down any nylium block that matches the nether sprout.
2. Place down the nether sprout.
3. Break the nylium block and look for a shadow on the ground ( that item doesn't even have an entity texture, you can only see it in your inventory).