My car doesn't start when it is parked under direct sunlight or it's very hot

My ford edge doesn't start when it is under the sun or it is very hot. When the temperature is very high or It is parked under the sun or there is a lack of shade it just won't start. The engine would keep rolling but it won't start. If I leave it and come back when it is under a shade or the sun as gone down it starts immediately like nothing was wrong. This is happening often now I can almost tell when it won't start cause of the heat or sun. I have been trying to park it where it is not under direct sunlight. A check was done, but I was told they couldn't find anything wrong.