entrance in China from Manila

Hello Mr/Mrs
My daughter in law, married to my Dutch son wants to go back from Manila to Shanghai. She has a working permit in China where she lives with my son and their daughter. She bought a ticket for Shanghai but was not allowed to start her flight in Manila.She has a working permit last December 2020 and has a residence permit for Shanghai and had a Sinovac vaccination in the end of May. She tried to reach the visa enter in the Hague but didn’t get an answer.
How can she succeed to get a permit to go home and see her daughter after several month’s.
D.Wolters=Father in law of Michelle Nocom.
Thanks for your answer