Why didn't you receive the short message of health punching in for postgraduate entrance examination?

I didn't receive the health punch-in message for the postgraduate entrance examination because the statistical period or time of the form was modified, which caused the system to be unable to recognize it. According to the relevant information, I didn't receive the health punch-in message for the postgraduate entrance examination, because the statistical period or time of the form of the personal sign-in system was modified, which led to the unrecognizable sign-in form information and the inability to sign in.