This is exactly what is happening when I log on to the site kindly provided by Mexbound: https://cvcovid.salud.gob.mx/
Finally received the email notice this morning. Printed out the certificate and it is incorrect. It said I had Sinovac but I had AstraZeneca, the lot numbers bore no relationship to the lot numbers on the vaccine we were administered. I looked for my spouses email and it had come in after bedtime last night. When I tried to download her certificate it said the 90 minute time window had expired. Others have reported the same type of errors and their weeks long attempts to get the certificate corrected to no avail. Looks like the end of the line.