Running nose every morning When wake up

Hi Guyz,
When i wake up every morning, i have running nose problem every morning. Water like fluid come out from the nose. It is continue. After some time it stopped by its own.
The day i eat egg, running nose problem stop after breakfast.
Another observation, the night i clean my mouth with some mouth wash and then go to sleep, next morning i don’t have running nose problem.

What is permanent solution of this and what is cause of this running nose problem.

Br
Thanks