https://github.com/xwiki/xwiki-platform/blob/d6cd1ead5802fcde6a83c36c87912b28d98145d5/xwiki-platform-core/xwiki-platform-web/xwiki-platform-web-war/src/main/webapp/resources/js/xwiki/actionbuttons/actionButtons.js#L227
This is probably because there's a weird use case with "inactive" boxes. They don't seem to be properly hidden when initialized.
