Recently had my wife's 2016 Explorer detailed and with the first rain the drivers side wiper bangs onto the passenger side wiper and makes a thunk every time they go back and forth.
Any clues what is going on and how to fix it?

 

If you look where the wiper blades make contact with one another, most likely one of the wiper arms or blades needs to be repositioned or they removed them and mixed them up when reinstalling them. When you see exactly where they contact one another you will probably see what needs to be changed. Most new vehicles use a different length blade for each side.

 

Does the driver's side have a wiper blade 26 inches long and passenger side 22 inches long ?