Can you share the code you were using to load local fonts in the editor?
WordPress 5.9 made it so the enqueue_block_editor_assets
no longer loads assets in the tablet/mobile views in the editor, so it’s necessary to use a different method now.
For example, add the @font-face
CSS to a stylesheet and upload it to your child theme, then do this:
add_filter( 'generate_editor_styles', function( $editor_styles ) {
$editor_styles[] = 'path/to/fonts/style.css';
return $editor_styles;
} );