If you haven't been to other places yourself, it means that someone else registered the health code with your mobile phone number, and then that person has been to other places. You need to appeal again, change your mobile phone number, and then change it to the relevant department. Otherwise, there may be a yellow or red health code, but you are actually fine. The original mobile phone number is no longer used. After being used by others, your health code turns yellow. Later, it was troublesome for a long time and was isolated.