Has anyone experienced this issue we've been having lately? When adding (or updating) a form on a landing page, there's no way to "let go" or release the form from your mouse pointer. The form stays attached, moves wherever you move your mouse and the only way to fix this is to close the page and start over again.
If this is reproduceable, please reach out to support. In general, it seems to be working fine for me, but if we can document your browser, we can have folks fix it.