This is a very normal phenomenon. When we eat, the saliva secreted by salivary glands around the mouth enters the mouth, and can be ejected if the amount of saliva is large. In particular, the submandibular gland excretory duct and sublingual gland duct are both open at the sublingual gland mound, which is located on both sides of the lingual frenulum (as shown in the figure below), which can cause what you said. There is nothing wrong with health. It is normal.
Caruncle under the tongue: a small protrusion slightly above the central incisor of the mandible.