Site Kit cannot connect to website – why?

We have an issue on a website that seems to have a lot on it’s function code, including somet pointless random username generator. No idea why.

But the warning that Skite Kit cannot run, is bizarre.
I read that things in the Header can cause it, and I found this:

remove_action(‘wp_head’,’feed_links_extra’, 3);
remove_action(‘wp_head’,’feed_links’, 2);
remove_action(‘wp_head’,’rsd_link’);
remove_action(‘wp_head’,’wlwmanifest_link’);
remove_action(‘wp_head’,’index_rel_link’);
remove_action(‘wp_head’,’parent_post_rel_link’, 10, 0);
remove_action(‘wp_head’,’start_post_rel_link’, 10, 0);
remove_action(‘wp_head’,’adjacent_posts_rel_link’, 10, 0);
remove_action(‘wp_head’,’wp_generator’);

Could this cause it?

Your site may not be ready for Site Kit

The site is on php 8.1, and a weird custom theme….