Are you using Voice Command Control ?
Mine was doing the same, if you are using voice control I suggest you may try and retrain it to your voice again.
It kept happening to to me as well, you may need to adjust the Voice Control sensitivity down.
I hope this helps.
my smart tv comand keeps popping up by itself whats the reason to this.. i have to scream out cancel thats the only way it turns back to normal..i have smart tv series 8 model num PS60E8000GMXX