Had the same issue a couple days ago... No issues at all since I got the phone and flashed jedi rom... Then one day it started acting up. I restarted and it kept doing it and then I restarted and cleared my cache and seemed to work.... Don't know if the clearing of the cache did it or just the restarts but it's back to acting normal.
I never leave my phone stock so I am not totally sure but maybe stock recovery? Turn off the phone then hold power and volume down then scroll to recovery select it and it will either go to it or you will have to hold I think the volume down button..
Someone else could answer this better than me. Have been running cwm or twrp ever since I went android.