Testing one by one does not scale. The testing tool opens the port of each address and returns the time in milliseconds, up to ten lines at a time.
The right order
First the port opens. Then authentication passes, with the right username and password. Then the country that shows is the country you bought. Last, the destination site answers what you expected. Failing the first step makes the others irrelevant.
An address that opens its port and shows the wrong country was delivered from the wrong group. One that does not even open its port is a candidate for replacement.