I've shared my KanBan Board with Public, double checked, that filter is set to public as well and double checked that permission scheme allows "browse" to public. Nevertheless I'm forced to log in, when trying to access the KanBan Board (via URL).
Goal is to give transparency to my users about open issues in our board and what is currently on the roadmap and prioritized without assigning a jira-software license - they just view, they do not edit.