@alexio If you give the related products container a custom css class, you can then add the following css code and remove the wishlist button (or icon) from just that loop.
.custom-class {
display: none;
}
The ‘ display: none; ‘ css code will remove that class and prevent it from loading, versus the css code ‘visibility: hidden’ and ‘content: none;’ as those just hide the class, display:none will prevent it from visually loading altogether.
Change .custom-class to the custom css class you assign to the Related Products container or section if using a builder like Elementor or Beaver Builder.
If you are not using a custom page builder (where its easy to assign custom classes to sections) then you can always edit the related-products.php file inside your themes templates folder (depending on theme, could be located somewhere else in the themes directory).
If you need furthur help, let me know.