Ever since the phone updated to the new 5.0.1, these things started happening:
1. My phone randomly reboots, and
2. Certain apps I moved to my SD card update to device storage instead of the sd card.
BTW, the "software version" is L720VPUGOD2
do a cache wipe on your phone..this is NOT a factory reset so you shouldnt lose any personal info in there. i cant remember the steps for the Samsung line so you'll have to google it unfortunately. its not an app cache wipe.
i believe you turn off the phone..then hold volume up,down,home and then the power button and it should boot you into a different screen upon start up..to be honest the last time i had to do that on a Sammy device i had to look it up through google. did it about a month ago on my GF's S4 through verizon..forgot the steps for it though.
I know it's painful but I did a factory data reset and it's like I have a new phone. So much faster and everything is working better. I wish I did that a long time ago.