Burndown chart not showing all values

[Michael Colucci]

Hello -

New user to Jira.  When looking at a Burndown Chart using original time estimate, it only shows values for two cards.  The remaining cards don't show any data on the chart; however the time estimates are populated from what I can see on the cards and their sub-tasks.  I basically can't find any difference between those cards that do display data and those that aren't.   See attached screen shots.  Any guidance on what might be causing the problem?

[Nic Brough -Adaptavist-]

At a guess, I would say the difference is in the sub-tasks.  I can't tell from the screenshots, but could you confirm that the two issues you mention are the "cards that do display data"?   And then that they are issue-level cards and the missing ones are all sub-tasks?