Checkbox is not checked, even though I do it with code

I'm writing a Java Game similar to Tetris for a school project. In the game I have a checkbox to turn music on/off.

My problem is that the checkbox, even though I set it to be checked, is NOT checked when I click it (don't understand me wrong, not AFTER, but before/at the same moment when I clicked it).

Okay so, in my code where I first initialize the checkbox I set it to be checked based on a variable provided in another class.

I tried debugging everything that is going on with the checkbox but I didn't get anything I didn't already knew.

Here's the code where I initialize the box:

music_cbox = TexturesHandler.getCheckboxTemplate();
music_cbox.setName("Music");
music_cbox.addMouseListener(Retris.getButtonHandler());
music_cbox.setLocation(Retris.WIDTH / 2 - 25, 250);

 // Setting it to checked based on the variable

if(!Retris.getAudioHandler().canPlay()) {
    music_cbox.setIcon(TexturesHandler.getUncheckedCheckBoxStyle());
    music_cbox.setSelected(false);
    System.out.println("box not selected");
} else {
    music_cbox.setIcon(TexturesHandler.getCheckedCheckBoxStyle());
    music_cbox.setSelected(true);
    System.out.println("box selected");
    }

The canPlay variable only gets changed when you CLICK the box:

if(box.isSelected()) {
    Retris.getAudioHandler().canPlay(false);
    Retris.getAudioHandler().stopMusic();
    System.out.println("Music disabled");
    box.setIcon(TexturesHandler.getUncheckedCheckBoxStyle());
    break;
    // (in a switch statement)
} else {
    Retris.getAudioHandler().canPlay(true);
    Retris.getAudioHandler().startMusic("Main_Menu.wav", "Main Menu", 0.1F);
    System.out.println("Music enabled");
    box.setIcon(TexturesHandler.getCheckedCheckBoxStyle());
    break;
}

I also tried box.setSelected() after setting the new icon and all, but somehow when i first click the box, it does the else part instead of the if part.