Tuleap - Cannot display Stories' Remaining effort on Sprint's burndown charts

I recently started using Tuleap to manage a college project. I have it hosted on https://tuleap-campus.org

Given I started my project a month and a half ago, I had to create a release, Epics, Stories, Sprints, Tasks for the past sprints... and I did not have any problem.

But, I can't seem to make the burndown charts work. They do not show the remaining effort for the stories of the sprint (this is, my burndown charts are empty).

Since I wasn't able to solve it, I decided to look for a solution. I found none, but I did find a tutorial, https://www.enalean.com/en/how-to-implement-scrum-with-tuleap, and I decided to follow it through. I imported the template the tutorial uses. And followed it step by step. Only thing I didn't do is to use the task tracker from the template, because I had some extra fields on mine that I wanted to keep.

After creating the first sprint... I realized I got to the same point.

My Stories hava a field, "remaining_effort", that's a float value, and user can fill it (field is to track development). And the sprints also have a "remaining_effort" field, that's computed and cannot be edited. I assume this is the field the graph uses to display the sprint progress.

I'd like to ask if anyone faced this issue before, and how they did to solve it. I couldn't find any useful information on the internet.

I just realized how to do: in each story/bug you must write (manually) the Remaining effort = Initial Effort:

Once you do this you have an "high point" on the Burndown chart.

Then as the tasks get completed you must set Remaining effort to 0 (or to a lower value if they are half done). Doing this on a daily basis will give you a reliable point on the chart.

You can see what happens as you start inserting remaining effort after days of not doing it: