meta title not working

Hi, I’ve installed your plugin and gone into the settings, then meta titles and descriptions, then home and set %%post_title%% | %%sitetitle%% as the title, but it isn’t working.
I’ve also gone into my page editor and edited a pages meta title and description but again it’s not working
I have added the below code to my themes functions file but still no joy

function seopress_theme_slug_setup() {
add_theme_support( ‘title-tag’ );
}
add_action( ‘after_setup_theme’, ‘seopress_theme_slug_setup’ );

Are you able to help?