WordPress 6.0 upgrade caused my custom function to stop working

Not working on WordPress 6.0: https://thealliance.health/for-providers/resources/provider-news-archives/

Working dev site on WordPress 5.9.3: https://ccahdev.wpengine.com/for-providers/resources/provider-news-archives/

Here is the function if somebody can spot what may have been deprecated:

function wpb_postsbycategory2022() {

$posts = get_posts( array(
    'category_name' = 'Provider News',
    'nopaging'  = true,
    'orderby'   = 'date',
    'order'     = 'DESC', // it's DESC; not DSC
    // There's no use setting posts_per_page when nopaging is enabled.
    // Because posts_per_page will be ignored when nopaging is enabled.
) );

$_year_year = '';   // previous years value
$_year_mon = '';   // previous year-month value
$_has_grp = false; // TRUE if a group was opened
$_has_grpy = false; // TRUE if a group was opened
    
    
foreach ( $posts as $post ) {
    setup_postdata( $post );

    $time = strtotime( $post-post_date );
    $year = date( 'Y', $time );
    $mon = date( 'F', $time );
    $year_mon = $year-$mon;
    $year_year = $year;
    
    // Open a new group for year.
    if ( $year_year !== $_year_year ) {
        // Close previous group, if any.
        if ( $_has_grpy ) {
            echo '/div!-- .year --';
        }
        $_has_grpy = true;

        echo div class='year' id='year$year';
        echo h2$year/h2;
    }
    
    
    if ( $year_mon !== $_year_mon) {
        // Close previous group, if any.
        $_has_grp = true;

        echo 'div class=month';
        echo span$mon/span;
    }

// Display post title.
if ( $title = get_the_title() ) {
    echo diva href='/?p={$post-ID}'{$post-post_title}/a/div;
    }   
    
    if ( $year_mon !== $_year_mon) {
        // Close previous group, if any.
            echo '/div!-- .month --';
    }
    
    $_year_mon = $year_mon;
    $_year_year = $year_year;
}

// Close the last group, if any.
// 
    
if ( $_has_grpy ) {
    echo '/div';
}
    
    
/* Restore original Post Data */
    
$output_string = ob_get_contents();
ob_end_clean();
return $output_string;
    
wp_reset_postdata();
}
// Add a shortcode
add_shortcode('categoryposts2022', 'wpb_postsbycategory2022');

Thank you for any assistance!