https://support.apple.com/en-us/HT201253
Sync your content using Wi-Fi
When the computer and the iOS device are on the same Wi-Fi network, the iOS device appears in iTunes. The iOS device syncs automatically whenever it's plugged in to power and iTunes is open on the computer.
Does anyone have automatic WiFi sync working, are there tricks to this? To be clear, WiFi sync is setup, and I can sync over WiFi manually by clicking the sync button. However, based on the link above, it should be syncing automatically. I add music to my library often, and even when plugging in overnight with iTunes open and on the same network, nothing new is ever on my phone in the morning, it only works if I manually sync.
Anyone know anything I'm missing?
Thanks.