thanks for your advise dude, i already rooted my phone, but now i want to flash a kernel for my phone and i really dont know which i should flash, because i dont want to brick it. Maybe i will go back to KitKat because Lollipop on s4 sucks.
Ok I'll help you.
Don't think about brick. If you do things in the right way you have no problem. :)
For your GT-I9505 the steps are these:
1 - Download philz touch recovery GT-I9505
or Download CWM recovery.
2 - Connect your phone to p...
I had the same problem on an old i9300.
How do you install your apps on the new rom? If you have used Titanium maybe the poroblem is this. Have you already tried to wipe cache and Dalvik?
Try this and tell me.