When you buy a second-hand Chaos pack from https://hive-engine.com , some player already bought the packs from a Splinterlands Official shop. They will receive the airdrop benefit, not you. So, I bought a lot of packs new directly from Splinterlands.io and received all my airdrop points when they came out. After I maxed mine out, I just buy the Chaos packs on hive-engine when they are so cheap at times.