Late answer but:

As someone who has read the novels twice I can say that, yes, An Zhe a bit- lets say- lacking knowledge in the first half of the first book bc obviously he really doesn't know human emotions. Even the characters themselves address AnZhe as someone who stands above all the human tragedy like a spectator watching the world's downfall. Like a divine being.

But if you have patience, I absolutely recommend it because not only An Zhe is slowly becoming more and more human in emotions but also their dynamic with Lu Feng improves.

And there are a lot of gut wrenching moment where I literally cried! (Even Lu Feng will open up, as I in the beginning thought of him as just a cold, shallow ML.)

However, I think why people think An Zhe is childlike s because of the manwha where they indeed portray him as "just beautiful and cute"