Gap in bust/torso area on DDIII?

So I just got a medium sized DDIII bust and put it on but noticed a very noticeable gap at the bottom of the bust and the torso area. Emailed VOLKS a picture and they said it's normal. However every other reference pic I've seen online doesn't have such a huge gap. I have the Rise Kujikawa body and wondering if there's just some difference cos time they were made? Or if a DDII bust would fit better? I'd like to get a large bust, just don't want it to look weird if she was wearing a bikini or something. With clothes on it obviously isn't a big deal.

It's probably the torso and inner frame not sitting correctly. If the flaps coming off the torso that fit behind the bust, are sitting on/or caught on the inner frame. This will cause the problem you're describing.