Can't use 3G internet on a certain app, please help!

I've got a iPhone 5 for about a year now, the first few months it's working probably but now it don't. I've got a app called "PPStream", when I clicked into this app, 3G internet would stop working, then I have to turn my phone or mobile data off then the internet would start working again. I can't access PPStream now but I really need this app. It does work with the Wi-Fi at home but the Wi-Fi is really slow and I don't need to update the app. Please can everyone help me to solve this.

I've tried some methods:

1) Erase all contents and settings.

2) Deleting the app then start all over again.

3) I've change the 'Blocked Cookies' to never.