As usual, if you want the facts, you have to read the Daily Mail.

https://www.dailymail.co.uk/news/art...try-China.html

These folks arrived October 3, in the middle of the National Day celebrations. In the past there have been indications that Beijing especially restricts TWOV at sensitive times. Recall all those with Turkish stamps refused TWOV en masse at Beijing a few months ago during some similarly sensitive time. (China has a lot of sensitive times, unfortunately.)

Of course we never know for sure.