This is weird, but Sometimes when I yawn, i guess it's a muscle maybe right below my chin/jaw bone. It's locks up tight into a ball it feels like. I usually have to massage it to get it to go back to normal. But it just happens sometimes when I have a big yawn. That's the only time it's happens. Not sure if it relates to this or not. Seemed like it might. Idk what it is even. If anyone knows let me know!