Skeleton Spawned with no AI

I was flying around with the elytra and I saw a skeleton. I wanted to dive bomb him/ smack him while I was flying. I hit him, and I saw the Crit particles, but no damage was done. so then I land on him, and he is just standing still, facing south, like mobs with the NoAI tag do. And he doesn't attack me. I was in an extreme hills biome. Also, I was in peaceful mode. I also found another one nearby. And when you run into them, you get pushed back.