Yes, this happens to me too. On those days that I wake up knowing that I will stutter all day, i notice two things. First, I didn’t get enough sleep or had a very tiring day the previous day and didn’t get enough rest. I know this because I yawn a lot throughout the day. Second, my mouth feels tighter and more closed than usual. I have to keep opening my mouth wide open to stretch it to loosen up the tight muscles in my face. Its weird.