Corn kernels should be coated with a thin layer of flour first, and then fried in oil, so that they will be tender and easier to be coated with egg yolk.

The following is for reference:

First, preparation materials: corn kernels, salted duck egg yolk 3, flour.

Second, if the corn kernels are not ripe, they should also be blanched.

Third, wrap the blanched corn kernels in flour.

Fourth, corn kernels are over-oiled. Fry until golden and crisp.

5. Press the prepared salted duck egg yolk into mud. Put a little oil in the pot, slide in the salty duck egg yolk, stir fry quickly, add a proper amount of salt, and stir fry the oiled corn kernels together in the pot. Duck eggs are yellow granules, wrapped on the surface of corn kernels, and taken out of the pot.

I have done this method several times and it has been successful. You can try:)

I think your yolk is always loose. Is it because there is no boiled water and then covered with flour?