Firstly, don’t be freaking jerk to people who are being helpful.
I have no way of knowing what you have or haven’t done and nor do I know if you have any technical aptitude at all. You are just a random person on a forum. Many people don’t look in options and even fewer in advanced options.
As for the Microsoft answer. Do you really believe the person who answered has ever even used a Japanese IME? Regardless of that, it was never stated it couldn’t be done, just the default behavior is to not do it, hence why you change options.
It works on all 3 of my pc’s at home. Also works at my work and the university I used to go to. In fact it has worked on everything I’ve every computer I’ve tried it on.Yes you will find a few people online complaining issues, you will find that about anything, you won’t find the opposite of all those millions of people it works perfectly for since they have no reason to talk about it.