Search results sort order failing: set by date only

Hi the default wordpress search seems to be for "piano"

 SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts WHERE 1=1 AND (((wp_posts.post_title LIKE '%piano%') OR (wp_posts.post_excerpt LIKE '%piano%') OR (wp_posts.post_content LIKE '%piano%'))) AND wp_posts.post_type IN ('post', 'page', 'attachment') AND (wp_posts.post_status = 'publish' OR wp_posts.post_author = 5 AND wp_posts.post_status = 'private') ORDER BY wp_posts.post_title LIKE '%piano%' DESC, wp_posts.post_date DESC LIMIT 0, 25  

however I need them all sorted by date first. My search results by date are skewed:

2020-10-25   2020-10-22   2020-10-20   2020-10-20   2020-10-16   2020-10-13   2020-10-10   2020-10-07   2020-10-06   2020-10-02   2020-09-30   2020-09-28   2020-09-02   2020-08-09   2020-07-21   2020-07-21   2020-05-21   2020-04-24   2020-03-06   2019-06-02  <- here it is skewed onwards 2019-06-01   2020-10-25   2020-10-24   2020-10-23   2020-10-23 

So I asume it is because the SQL query sorts by title first.

So I tried this solution:

 function changeSearchSort( $  orderby, $  query ){     global $  wpdb;      if(!is_admin() && is_search()) {         $  orderby =  $  wpdb->prefix."posts.post_date ASC";     }     return  $  orderby; } add_filter('posts_orderby','changeSearchSort',10,2);  

from here How do I change WP search results order?

and it does not work.

I have tried this:
a) disabled all plugins
b) different themes

still not working.

Help appreciated

cheers

Ben