@bluesmanbill
Regarding the nerve. It is the Vagus nerve. I runs from brain down to body and is quite active in things like this.

I was told by Mayo PCP that it was sensitive and reacting excessively to irritation and thus the developing of mucus.

When I was having tachycardia after eating this same nerve came up. Can't remember exactly but the nerve is responsible to what in your body gets the blood focus. when you eat it does there for digestion and can trigger VTAC episodes. A wonder for me as did not anything.

What I was told to do is limit my eating, Sit straight up. It did help with the tachycardia.

With the mucus in throat I think someone posted it got worse and triggered the increase when eating yogurt. I do remember eating yogurt and was at water aerobics and was constantly having to clear my throat.

I don't usually have issues in early morning but have kept a log now of what I eat and see it if contributes to the mucus. Right now I do know yogurt is a trigger.