[deleted] it's actually using localStorage.
A dirty trick to make it reappear would be to clear the localStorage key on each page load, by adding the following to custom Footer HTML:
<script>window.localStorage.removeItem('welcomeHidden');</script>
People can still close it, but each time they reload the page it will be visible again.
EDIT: fixed my code that was incorrectly using clear() instead of the intended removeItem(). The previous code would clear all of the localStorage for the forum 🙊
