I just checked the burndown chart for our last sprint and the plots for closed points, remaining points don't seem to display anymore:
https://phabricator.wikimedia.org/sprint/view/935/
Also, some tasks were not closed before the holidays so I did that earlier before looking at the burndown chart. When I noticed it wasn't plotting anything except the ideal points, I edited the end of our sprint to Tuesday in the hopes it would unbreak. This resultedin the plots "start points" and "remaining points" being displayed but incorrectly (starting Jan 1st and incorrect values).