Sorry to hear that you are having to deal with this as well! It's complete BS.
I also accidentally selected the box stating I was a "Doctor" and have been going through hoops trying to have someone update my application and tell me whether or not that incorrect selection is the reason I am being asked to complete a health exam. At first, I immediately submitted the "Update Details" form (#1023) that is available on the immigration account because I was told by the home affairs team that "doctor" refers to human physicians only. Unfortunately, my initial visa review still came back requesting a health exam. I then spoke with another home affairs representative and, after 20 minutes of waiting, was asked to submit a physical copy of the form I submitted online because that was "internal policy" for details that might affect the health exam. How does that make sense? It doesn't even state that anywhere on the website.
I'm close to just scheduling the health exam because I'm pretty sure that submitting an online request to update details does nothing. Please post if you have any luck getting the issue corrected!