Preview of used fonts in Backend and ALB …

I am now having problems with self-hosted fonts for the first time. In the frontend everything runs as before without problems.
Where problems appeared now was in the backend. First, where the selected fonts are chosen : “General Styling” the previews were not displayed.

since I loaded the fonts using a custom plugin and only via wp_enqueue_scripts I thought I could additionally fix the problem via admin_enqueue_scripts. There – see above – the previews were then also displayed in the correct font.

Unfortunately, the problem was not fixed for the ALB elements that had the config[‘preview’] set to also show the fonts in a correct preview in editor mode.

What else could be the problem?

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PS:
I embed my local hosted font to the theme setting by:

function avia_add_content_font($fonts){
    $fonts['Scripter'] = 'Scripter:400';
    return $fonts;
}
add_filter( 'avf_google_heading_font',  'avia_add_content_font');
add_filter( 'avf_available_google_fonts',  'avia_add_content_font');