Issues with apps loading on the ATIV SE

[CEGNJ31]

I have had a lot of issues with my Facebook app where I can't Like or even post things at random times. I always check my internet connection and it's always strong, and I never had so many issues with my Android phones. Is this a WP issue or a Samsung issue? Also, each time I open Pandora & choose the station, I get the error message that it won't load, but I click 'OK' and then it plays. Happens every time. I was so excited about the WP and love the interface, but I feel like more and more things aren't working, and to top it off, I still don't have 8.1, which was the main reason I bought the phone over 2 months ago!