transit over China

Thank you Mark.
You wrote me
"Hi, you are eligible for 24-hrs free transit for Warsaw--Frankfurt-Beijing--Guangzhou--Sydney, and no entry permit is required. But you need to apply for an entry permit beforehand for Auckland--Guangzhou-Beijing--Zurich--Warsaw."

Why for the route Auckland--Guangzhou--Beijing---Zurich--Warsaw I neet transit visa???
these are 2 separate tickets one is Auckland--Guangzhou--Beijig and second: Beijing--Zurich--Warsaw

thank you for the answer
Michal