According to the current patent law, this situation may exist, provided that when China people applied in China, they had applied for the British patent right, but it was not made public.
At this time, because the patent right has not been made public, others should not know, so the application of Chinese people is novel. At the same time, because the British only applied for a patent in Britain, but not in China, the application from China does not harm the prior rights of the British, and the application is valid at this time.
However, if the British patent has been published, it constitutes the prior art of the patent. Whether British patents are still protected or not, China people's applications are no longer novel, so they can't get any more patents.
I hope the answer will help you.