I have had my S4 for nearly 2 months & love it except I don't know if this is normal or not............but when I turn my S4 off say for the night & turn it on in the morning, I have to manually connect to whatever wifi everytime (my old S2 used to connect automatically) if I don't connect then it uses my mobile data if its switched on,never had this problem with my old S2,it was on & ready to go when I switched the phone on.........
Katie.
Katie.