Yeah, that placement is odd and not how the AddToAny displays on most sites.
Looks like you currently have AddToAny set to appear at the top of posts in Settings > AddToAny > Placement, which usually looks great, but the post is technically the first thing appearing on your pages because there’s no ‘real’ header on your pages — so the buttons are appearing at the very top of the site.
The site has a sort of ‘pseudo’ header through visualcomposer. This visually looks normal, but you’ll continue to run into issues in the WordPress ecosystem where plugins/etc. expect a real header element. To save you some issues down the road, I’d recommend removing that visualcomposer “header” in favor of using/customizing your actual astra theme’s header. (Alternatively, I see visualcomposer offers their own real header behind a premium version.)
For centering underneath, set AddToAny placement to the bottom of posts, then to center-align the icons just add a line of CSS code to your Additional CSS box in Settings > AddToAny:
.addtoany_content { text-align:center; }
