kindle app issue with ipad

I have a kindle app on my ipad and have many books on it. I recently got a new book delivered to my ipad from amazon, but I can't download it. I get a messsage saying "no internet connection". However, I do have an internet connection on this device and it is connected, able to open websites etc.

I've never had this happen before. Any way to get the device to register that it is online within this app. I've gone to the amazon site and resent the book several times, and each time it is delivered successfully. It just won't download.