itunes not syncing podcasts over wifi

I have a Mac Mini that I sync my IOS devices with successfully over wifi everyday. Randomly, when I go to play a podcast, that can be played within iTunes the day prior, doesn't work on my IOS devices. After syncing the night before, I go to play the podcast and it prompts me to download it over celular, which I'm trying to avoid. Any help would be great!

Iphone 5

iPad Gen 4

iPad Mini

Iphone 4 s

MAC Mini 2012 Version

All running the lastest IOS and version of Mavericks.

Thanks,

Stephen