Bugg after Update

Hello,

On my website : https://www.1stmeat.com/accueil and after updates the theme :

1 – I switch off “Product navigation”, but it’s display. Why ?
2 – Why my custom css doesn’t work ? How i can delete “Informations complémentaires” on my product page
3 – I switch off “Related product” navigation, but it’s display. Why ?
4 – Why I lose all my setting for colors and custom css ?
5 – How i can edit search button and don’t display in full page the search ?

Thanks