Bring Home The Beacon is supposed to trigger when a beacon that you have built activates. But this advancement does not trigger if you have provided the beacon with sky access after building it. This only occurs in the Nether.
To reproduce:
1. Create new world.
2. Place some blocks.
3. Build a beacon underneath them.
4. Remove the blocks.
5. You will not get the advancement.
6. Build another beacon, this time with sky access.
7. You will get the advancement.
Works for me.