
Considering how elise proved to be even more valuable to the king when she disclosed important information about the expedition, becoming more lady like and humble, and even plans to be a doctor - one of the most honorable profession in the empire; I can see it as normal when the king reacted that way. Those are qualities befitting an empress as he saw it. Anyone would be suspicious knowing that an 15 yr old noble lady would perform miracles when she has just taken up the profession.

Despite her new memories and thoughts it was still the ORIGINAL plan to make her empress instead of a doctor. With her skills it would be more beneficial for his own personal use in bettering the kingdom if she's nearby whereas if she's in the hospital her priority is the patients instead of standing by his son.

That's because she didn't believe that Elise did change and he didn't believe that Elise is capable enough as what the doctor said but I think everything will be okay if Elise pass the examination for the license or something because this proves her skills and abilities, although the king might not believe it again and make other complicated things but Elise should be able to pass it, until the king saw Elise's real capabilities (note: this is just my speculation). But if he still insist on making Elise the queen for his son, that just shows he really love Elise to be his daughter in law.
the kings kinda an asshole, hes very selfish