Wifi Connected but 50:50 Wifi:Cellular Data

I've got a lumia 920 with Amber update. My wifi is enabled and connected (I've read through many threads about this issue post-Amber) but about half of my data usage is still coming over cellular rather than wifi. I am in wifi-connected environments for most of the day, and I do not do much texting or calling. How can I determine whether my apps/livetiles are defaulting to cellular and whether I can direct them to wifi? I would have thought the OS would do that automatically when wifi is enabled...

Thanks,

DBOP

Is your wifi set to always on in the advanced settings??

If you mean "Keep WiFi on when screen times out" the answer is Yes, that is checked.