iPhone 6 will not sync over WiFi

Over the past month I've noticed that my iPhone 6 will not sync over wifi. It was working with no issues about 2 or 3 weeks ago and now I cannot figure out what is going on. The check box is selected for wifi syncing in iTunes and everything appears to be normal. I have tried several other options from internet forums but nothing seems to work. I had this exact same problem with my iPod 5th generation but that is entirely another headache within itself. I am so frustrated with Apple products lately.