Happy new year,
I am a developer from Vietnam. I have been working with Wordpress for a long time. I can do plugin, create time and customize wordpress. I have read your requirement carefully, I'm interested in it and know how to fix it, and yes, no plugin, we just need to modify some config and update database content. It is very easy for me, I can finish it within 1.5h.
Let me help you fix it.
Thanks
Jimmy