What I expected to happen was...:
I expected to receive the "Bring Home the Beacon" advancement after I had crafted a beacon block and activated it using iron blocks

What actually happened was...:
I crafted a beacon block, I activated the beacon block with iron blocks, and I didn't receive the advancement.

Steps to Reproduce:
1. Create a new world

2. Travel to the nether in order to unlock the "Nether" tab of advancements

3. Craft a beacon block

4. Place the beacon block on top of a 3 x 3 platform of iron blocks to activate the beacon

5. You will not receive the "Bring Home the Beacon" advancement like you should