Health Check before Letter of Invitation

Hello, I was offered a job teaching science and math in China. It looks like a great job! However, the process outlined by the school is different than what is stated in this article.

The school had me complete a health check first here in America and then get the health check notarized at a Chinese embassy before issuing me the letter of invitation. I did this and sent the health check to the school but unfortunately, the health check failed inspection because it lacked a stamp. The school is going to send me back the health check for more stamping. Seems like a lot of trouble.

Are these new regulations? Is the new requirement now that a health must be done and properly notarized BEFORE the school can issue a letter of invitation?