China's patent system is the first to apply, and the patent right applied earlier is valid. What you said may happen. However, it should be noted that because the utility model has not been examined, the patentee generally needs to submit the patent evaluation report of the utility model to the court when claiming his rights, which is equivalent to the examination of the utility model. The examiner will find this problem, which will lead to the failure of the claim.
2. Patents are regional. Patents applied for in the United States can only be protected in the United States, while patents applied for in China can only be protected in China. That is to say, if others apply for patents in Japan but not in China, they can use this technology at will in China, as long as they are not exported to Japan.