Reason 1: Health code always logs in again, which may be caused by network delay. Personally, I suggest finding a place with network preference and trying again or logging in at another time.
Reason 2: During this period, the health code is constantly updated, and you frequently appear in various places. The more times you log in, the more you need to log in again.
Reason 3: The main reason is that you need to look at the itinerary every time you refresh the health code. This requires you to enter the login operation before you can query.