Price widget not working correctly

Hi there,
few weeks ago i’ve opened a thread tell you that there was a problem with the woocommerce priice filter widget, but after answering the first time ( @stuartduff ) you guys forgot about the thread. So here again I show you what the problem is:
Original message:
I’ve tried the filter on a clean install and woocommerce sends a wrong query to SQL.
In fact with taxes activated (all 22%) and doing any search with the default woocommerce price range filter, it sends a query FROM price without tax (wrong calculated: for ex. input 5, without vat should be 4.1€ + 0.90€ (22%) [5/1.22% = 4.10€] = 5 but the input sent is 3.9€ which i think is derived like this: 5 * 0.22 = 1.10, 5 – 1.1 = 3.9€);
and the TO is like the input.
See the example:
Url: https://localhost/shopping/negozio/?min_price=300&max_price=488
The query is:

SELECT SQL_CALC_FOUND_ROWS wp_posts.ID
FROM wp_posts 
INNER JOIN wp_postmeta
ON ( wp_posts.ID = wp_postmeta.post_id )
WHERE 1=1 
AND ( wp_posts.ID NOT IN ( 
SELECT object_id 
FROM wp_term_relationships 
WHERE term_taxonomy_id IN (7) ) )
AND ( ( wp_postmeta.meta_key = '_price'
AND CAST(wp_postmeta.meta_value AS DECIMAL(10,2)) BETWEEN '<strong>234</strong>'
AND '<strong>488</strong>' ) )
AND wp_posts.post_type = 'product'
AND (wp_posts.post_status = 'publish'
OR wp_posts.post_status = 'private')
GROUP BY wp_posts.ID
ORDER BY wp_posts.menu_order ASC, wp_posts.post_title ASC
LIMIT 0, 10

Attached you can see images of the configuration:

View post on imgur.com

Thanks

Regards

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