It's Malware in one of the apps installed.. the easiest solution is to simply start from the last apps installed and work your way backwards but reset the phone after every uninstalled app.. for me it was a beat making app but for others its the zcamera.. most apps ask for permission to do this and we grant it without knowing or caring.. hope this helps .. no need to send it out unless there's screen damage which can also cause the problem.. it was driving me crazy with yt and fb as well and now it's perfect again ..