I had this same issue on my 5S and a majority of my friends with that particular model seems to be experiencing that as well. In any case, after browsing the a

I had this same issue on my 5S and a majority of my friends with that particular model seems to be experiencing that as well. In any case, after browsing the apple support forums, I decided to try a few of the workarounds there and the only one which worked was by setting my 2.4ghz interface to b/g(legacy)-only mode. It was an acceptable fix since all my other devices were on the 5ghz and I don't really have any other option(7.1.2 was great for me, shouldn't have upgraded).