Business & Hobbies EP pre-purchase is not available in my region (steam)

Hey, I am a simmer living in China. Recently I watched the latest trailer of Sims 4, and I am really get into the idea of opening a home business and the aesthetic of northern europe. However I am not seeing the pre-purchase page on steam. At first I think it's just fine, I am okay with it and just wait the team to put the page up. After like 2 or 3 days, I still did not get the page. Till recently the game booted up with a such a large adscreen (previously the event adscreen), encouraging me to check out the latest dlc pack, but I just cannot see it, again. It mentions that the item is not available in my region. Finding things weirdly, I asked other simmers to check if that page is available in other regions, and the page is actually there and works. I just don't know what is actually happening here.