Why cannot we modify original estimate in a started sprint ?
I fear you'll say this is by design, this affects sprint scope, you should not have unestimated issues in sprints...
Unfortunately for us it's often the case, that the sprints starts with 60 issues, most of them have no original estimates yet, because the estimate (the analysis part) will only arrive during the sprint, and for some issues halfway through the sprint, because estimation/analysis in our case is part of Sprint Work!
Any thoughts ?