Filter function for adding attribute scope to th won’t run

Hi Tobias, thanks for this useful plugin.

I was trying to add scope="col" to table headers, like rachitaora in this thread (https://ww.wp.xz.cn/support/topic/tablepress-ada-accessibility/) and you very kindly provided the following code.

function ada_tablepress_add_scope(  $tag_attributes, $table_id, $cell_content, $row_number, $col_number, $colspan, $rowspan ) {
    if ( $row_idx === 1 ) {
        $tag_attributes['scope'] = "col";
        return $tag_attributes;
    }
}
add_filter( 'tablepress_cell_tag_attributes', 'ada_tablepress_add_scope', 10, 7 );

The only problem is that I get the following error when adding it:

Fatal error: Uncaught TypeError: Argument 1 passed to TablePress_Render::_attributes_array_to_string() must be of the type array, null given, called in /app/public/wp-content/plugins/tablepress/classes/class-render.php on line 672 and defined in /app/public/wp-content/plugins/tablepress/classes/class-render.php:733 Stack trace: #0 /app/public/wp-content/plugins/tablepress/classes/class-render.php(672): TablePress_Render->_attributes_array_to_string(NULL) #1 /app/public/wp-content/plugins/tablepress/classes/class-render.php(371): TablePress_Render->_render_row(4, 'td') #2 /app/public/wp-content/plugins/tablepress/classes/class-render.php(135): TablePress_Render->_render_table() #3 /app/public/wp-content/plugins/tablepress/controllers/controller-frontend.php(645): TablePress_Render->get_output() #4 /app/public/wp-includes/shortcodes.php(325): TablePress_Frontend_Controller->shortcode_table(Array, '', 'table') #5 [internal function]: do_shortcode_tag(Array) #6 /app/public/wp-includes/shortcodes.php(199): preg_replace_callbac in /app/public/wp-content/plugins/tablepress/classes/class-render.php on line 733

If I comment out the if statement in your code, it runs without error, but that adds scope="col" to all rows, which is not what I want.

Do you know how to fix this error?