Going back to MainMenu from other level. (Problem)

Hello guys, im going to try to explain it the best i can since my english is not the best.

I have an Scene called "Menu", that's the first scene to load, its a very beautiful main menu with a lot of animations, things moving , a song.... etc

Then I have some buttons and one of them is "Start New Game". And when you press it, it loads "World1_1".

Well the problem comes here, I've made a pause menu inside the game, that's working very good. Inside that pause menu i have 3 buttons.

Options, Quit and Return to main menu

Options = Works
Quit = Works
Return to Main Menu = yes and no. I explain this.

It actually loads the "Menu" scene, but without animations. I've tried to fix it but no way.

If you could help me.

Here's the code of the Return to Main Menu button: (I use On click () function)

public void MainMenu(string selGameLevel)
     {
            SceneManager.LoadScene(selGameLevel);
     }