debug not working inside a WordPress filter

I’m trying to debug a function that is run on the WordPress attachment_fields_to_edit filter. When I run something like

do_action( 'qm/debug', $form_fields);

or even

do_action( 'qm/debug', 'test');

… from within the function run on that filter

and view a page like https://localhost:10003/wp-admin/upload.php?item=126

nothing shows up in the “logs” tab under Query Monitor.

Full code of the relevant part of functions.php

function my_attachment_fields_to_edit( $form_fields ) {
	    // debug not working here
	    do_action( 'qm/debug', 'test');

            // apply to these taxonomies
	    $taxonomies_arr = ['submitter_name', 'submitter_email', 'creator_name'];
		foreach ( $taxonomies_arr as $taxonomy ) {

	    // Do nothing if the Submitter Email field is not in the fields list.
	    if ( ! isset( $form_fields[ $taxonomy ] ) ) {
	       continue;
	    } else {
		    // Get the term by its slug.
		    $field = (array) $form_fields[ $taxonomy ];
		    $term  = empty( $field['taxonomy'] ) ? null :
		        get_term_by( 'slug', $field['value'], $taxonomy );

		    // Use the term name.
		    if ( $term instanceof WP_Term ) {
		        $form_fields[ $taxonomy ]['value'] = $term->name;
		    }
			}

	    }
            // debug not working here
	    do_action( 'qm/debug', $form_fields);

    return $form_fields;
}

add_filter( 'attachment_fields_to_edit', 'my_attachment_fields_to_edit' );

Debugging in other places works as expected. How can I get these debug messages to show?

PHP 7.4.1
WordPress 5.9.3
Query Monitor 3.9.0

• This topic was modified 2 years, 10 months ago by mrengy. Reason: cleaned up code, added basic example
• This topic was modified 2 years, 10 months ago by mrengy. Reason: added versions

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