It works as it should, it is the same as it was on other normal servers, you are accustomed to it now that it will no longer return after 30k hp.
See dende heal max to 9.5k or 11k never for heal 30k, it was 4 years ago. https://www.youtube.com/watch?v=X2vZKK9cEB0&t=70s
So, change the "Ultimate Kami's Healing Technique" skill description.