I am having the same issue. Did you ever find out what was going on? I replaced the battery and a control module that was recalled. The next day it didn’t start.I have had my Fiesta for about 3 months now and already the issues have begun. My stereo system was the first problem to start. Randomly there is a loud pop noise in the speakers and the entire system goes out. From reading other threads I took the advice to pull the fuse behind the glove box, wait a few minutes, then re-insert. That gets it going again but seriously?!, I should not have to do that regularly just to listen to my bloody music!
Now the engine has issues. I turn the key, all lights come on everything is as it should be minus a running engine. Turn the key to the off position and try again and it starts up. This has happened three times in the past week and a half. My car has 45k miles on it and I am now starting to wonder if the previous owner got rid of it because of these same issues. I love my Fiesta but am now wondering if this is just the beginning of a long line of problems.