This started happening with me, a while back. And I never suspected it was from kava.
I think it's a common reaction for people wit anxiety, so I thought I was doing it because of anxiety.
I knew about a "difficulty swallowing" issue that can result from kava, but not this.
But I think it's important to deal with it, because if I'm not mistaken, it can lead to that condition TMJ, which is not fun