Chongqing

Hi I'm looking to get a flight to Chongqing from Vietnam in a few days and get my 144hr visa on arrival. The only flight available is late at 21:45 and arriving at 00:45. I have heard story's of people being refused to board the plane as no one will be there in immigration to do the visa. Are there specific opening times or will I be okay travelling to Chongqing at this time and sorting my visa when I get there late?

I have all the required documents needed.