iBooks keeps asking me to turn on wifi
(wifi-only iPad mini 1st gen, iOS 8.1.3, iBooks 4.1.1)
It wasn't something I noticed right away, as I hadn't used iBooks in a while. But when I open iBooks, I always get a pop-up telling me I need to enable the wifi. That pop-up has always been really annoying even on other apps (I bought the wifi-only iPad for a reason), but now that it's appeared in iBooks, it's the final straw. I'm not interested in using my iPad to buy stuff, or in seeing the New York Times Bestseller List, so I don't want it to be bugging me about the internet every time I want to read something.
Is it possible to disable this?
iPad mini Wi-Fi, iOS 8.1.3