They did dub their own characters which is unusual for chinese period dramas.
I also like it more when it's not dubbed, this is the reason I don't really watch Chinese drama. Honestly I started to watch this drama because I read somewhere that is not dubbed, and I really enjoyed it, it has a different vibe when the actors use their own voices. I'm also very surprised how good the actors are, I personally am impressed of Jing Bo Ran's acting . I'm sorry if Chinese people don't like it.