I have one of the issue regards to standard reports - below you can see a burndown report which looks completely the same also in sprint report. As you can see I have picked an Active sprint. Here i see something like 644 hrs as starting scope /original estimate amount.
Original estimate:

Remaining Estimate:

Below you can see an overview of estimation on sub-task level which is significantly higher 502 days/4016 hrs (sub-task level) than 132 hrs (burndown) specific to original estimate or 219 days/1758 hrs (on sub-task level vs. 644hrs (burndown)

Please help me on this issue.