Tests automatically enter pending when they're created. It can take anything from a few seconds to a few hours to process. During this time PreFlight is learning your UI and ensuring that your test will be robust enough when required to run again.
It is perfectly normal for some tests to take seconds and others on the same UI to take a few hours. As time passes and PreFlight learns more about your UI as well as other UI this time will decrease to the point where every test takes only a few seconds to initially run.
If you have any questions - don't hesitate to contact us - [email protected]