u/CuboidMC

So basically I have a creative minecraft world. I built a full beacon. And then I went to the nether to mess around, and died in the nether when I switched to survival. But when I respawned in my village, I was around 30 blocks next to the beacon, and I got the beaconator advancement, even though it was expanded from one layer to a full beacon like 20 minutes prior. Why did I on;y get the advancement after I died?