German National - Route: Germany - Turkey - China - Russia - Germany

Hi,

Would like to understand why my Dad cannot board the plane to Shanghai, according to the regulations I read on this and other websites, he is eligible for 144 hours free transit visum in Shanghai.

- He is a German national with a German passport
- He has a departure) and returning flight with arrival on the 21 December and departure on the 27 December
- His route is Berlin - Istanbul - Shanghai and returning from Shanghai - Moscow - Berlin

We are told in Istanbul he needs a VISA, so I am curious to understand why?

Thanks so much for your help!
Lin