I’m not sure why there’s a non-breaking space being added to the front of your excerpt. It would be best to find out what is putting that there. But in the meantime, you can add this to your theme functions.php ( or a simple plugin ) and it should take care of it.
//* Remove non-breaking space from beginning of paragraph
add_filter( 'the_excerpt', function( $excerpt ) {
return str_replace( [ '<p> ', '<p> ' ], '<p>', $excerpt );
}, 999, 1 );