Hi Curzey,
Some updates 
The day before yesterday around midnight I checked the url and all the prices were good! NO changes, just expected.
But the next morning, I wanted to check again and all the prices were back - obsolete.
No cache, no nothing. I can’t believe it! How can the price be right at midnight and the next day, wrong.
I may have a clue:
Shopify code (documentation), but in the documentation the price is of type “String” whereas schema.org recommends a “Number” type :
<script type="application/ld+json">
{{ product | structured_data }}
</script>
Example of a working LD JSON from another business on Shopify - prices displayed correctly :
{"@context":"http://schema.org","@type":"Product","aggregateRating":{"@type":"AggregateRating","ratingValue":4.790153980255127,"reviewCount":1625},"name":"Boost Curl - Gelée coiffante hydratante - 250ml","image":"https://www.secretsdeloly.com/cdn/shop/files/BC700x700fondblanc_1_large.jpg%3Fv=1701073773","offers":{"@type":"Offer","availability":"http://schema.org/InStock","price":19,"priceCurrency":"EUR"}}
My Client LD JSON :
{"@context":"http://schema.org/","@id":"/products/creme-contour-des-yeux-au-collagene-tirtir#product","@type":"Product","brand":{"@type":"Brand","name":"TIRTIR"},"category":"Soins des yeux","description":"Donnez un coup de jeune avec la Crème Contour des Yeux TirTir au Collagène, pour des yeux visiblement plus lisses et plus fermes. Grâce à son roll on, profitez d'un massage délicat pour re-pulper votre contour des yeux.","gtin":"8809679692514","image":"https://www.aboutskincompany.com/cdn/shop/files/tirtircollagenliftingeyecreamtheskincounter2_png.webp?v=1716899881&width=1920","name":"TIRTIR - Crème Contour des Yeux au Collagène","offers":{"@id":"/products/creme-contour-des-yeux-au-collagene-tirtir?variant=54624661078351#offer","@type":"Offer","availability":"http://schema.org/OutOfStock","price":"28.90","priceCurrency":"EUR","url":"https://www.aboutskincompany.com/products/creme-contour-des-yeux-au-collagene-tirtir?variant=54624661078351"},"sku":"2","url":"https://www.aboutskincompany.com/products/creme-contour-des-yeux-au-collagene-tirtir","aggregateRating":{"@type":"AggregateRating","ratingValue":"5.0","ratingCount":"2","reviewCount":"2"},"review":[{"@context":"https://schema.org/","@type":"Review","identifier":"frev_oYdsDy4","datePublished":"2024-07-01T14:56:24.985Z","author":{"@type":"Person","name":"Camille"},"reviewBody":"Celui-ci c'est clairement mon chouchou dans cette nouvelle skincare proposée suite à mon diagnostic de peau réalisé au concept store ! A l'âge de 38 ans il était temps de prendre soin de mon contour des yeux qui présentait quelques ridules. En 3 mois d'utilisation, mes ridules sont devenues quasi inexistantes. Facile d'application, la juste dose de produit en une seule pression et son roller effet froid finiront de vous convaincre, l'essayer c'est l'adopter !","reviewRating":{"@type":"Rating","ratingValue":"5"}}]}
I really don’t think it will have such an impact because via VPN in other countries, the price is right but I’m open to all possibilities and leads.
And site:[product url] just shows me, even in France. Should I wait any longer? The last changes were made on March 11-12.