Since story #7954 (in 2015) and git #tuleap/stable/c4cb6731aad4f2f370e8eeb0a296a5c03404ca3e, Tuleap's Kanban has used a custom JS scrollbar implementation to make the scroll bars smaller than the default from the browser.

Finally, 10 years later, since request #42610 we have a way to style the scrollbars using CSS only. We should use that and remove the dependency on ng-scrollbar. Using CSS only will be faster, with less code and no bugs (sometimes the custom scrollbar did not let you go to the end of a Kanban column).