Hello,
It seems like when you turn your head and yawn; your esophagus gets shifted a bit. This puts pressure on it and constricts it. The esophagus does have some range of movement laterally in your neck, so this isn't really too serious of a problem. If you can manually pop it back into place than that is good. Maybe if you can go a while without this happening, more connective tissue will form to hold your esophagus into place better.
Hope this help you!