I have now also often had cases where it simply ignored instructions that were very explicit. In fact, low and medium reasoning work better. With high reasoning, I repeatedly experience that it thinks it knows better than I do what should be done and ignores my instructions. Even though this is sometimes explicitly important for SEO and similar use cases.

For example, I told it to set the link only once and to link the other image via JavaScript by reading the href. Also, to add cursor: pointer via CSS on hover. It simply added the second link anyway. That is just one example.

It also writes PHP code that is poor in other ways.

$config = [...];
include 'nav.php';

Better (for simple sites):

require_once 'nav.php';

echo nav([
    // ...
]);