Intra-china awards increased to 17.5K miles. What you are seeing are instances of broken fare awards which DL has been pricing out for a couple years now. You can see the fare construction by bringing it up on the website and clicking on the fare rules. You will see the 35K awards are a combination of two separate 17.5K awards due to the connection (fare code YSM175). You can find 17.5K awards on this route on the CZ non-stop flight. There is nothing inherently "incorrect" with broken fare award pricing. They are presented in cases either where there is no inventory available on a through routing (due to married-segment logic) and the broken fare is either the only option, or it is a cheaper option than whatever award bucket is available on the married-segment through routing.