For example, when you move the mouse over the categories, it is the word that is shaded and not the white square below, as it was presented in the demo.
Also, the page background is not full width. It is the background image that is inserted, instead of seeing the background or the products are not nicely presented.
https://carolinepiche.com/categorie-produit/art-print/
https://carolinepiche.com/categorie-produit/oeuvres-originales/
https://carolinepiche.com/categorie-produit/pierres-cristaux/
In fact, some categories are full page background and some not. And some have three columns and on the other sometimes two. And sometimes it’s 3 wide on the first row, just 1 product in another row, another three wide, and two…it’s not 3 wide all over the page.
See the following screenshots please. So according to the demo imported, it’s not totaly the same.
your demo https://xstore.8theme.com/demos/2/artmaxy/product-category/oil/
caroline website, the background is not full width : https://carolinepiche.com/categorie-produit/pierres-cristaux/
And finaly, into this page : https://carolinepiche.com/categorie-produit/galets-de-mer/ only two colomn instead of 3, like others. And similar in this page : https://carolinepiche.com/categorie-produit/oeuvres-originales/
So you know your demo more than me. You can test all pages and see bugs over there. specialy those under boutique.
Thanks!!