Thank you for posting this observation. This is a great resighting, for a species that is not ringed often in Hong Kong and as far as I know has no previous resighting information.
I am fairly confident that the individual here is AB09649. This bird was ringed at Mai Po Nature Reserve on 29th October 2018, when it was going into a roost with many other Yellow Wagtails.
I'm sorry that I can't read the Chinese in your original post. Can you confirm where this photo was taken please? Thank you.
