Since Bootstrap 4, ClipboardJS does not copy the value in the clipboard anymore as Bootstraps modals give the focus to another element. As the focus need to be given back to the correct element, ClipboardJS has to be updated as the container parameter is only added in v1.7. We were in 1.5. That container parameter allow to give the focus back to the correct element. See doc on https://clipboardjs.com/ + Issue : https://github.com/zenorocha/clipboard.js/issues/155