I am also facing the same issue please get it fixed

I've encountered this as well now, and can describe the scenario that causes this issue.

This happens if I'm moving a task from one collumn to another within the swimlane, but there are no other tasks in the rest of the swimlane. I am dragging into a  collumn that has 4 possible state transitions, but cannot drag the task up and down to select the state transition that I want.  It depends on whether I click and drag on the top or the bottom of the task before I start dragging, as to which transition I get.  

If there is simply 2 or more tasks anywhere in the lane, then there is no issue here, you can drag the task up and down within the lane and select the correct state transition.

Many thanks for raising this bug. Since there has not been any customer activity on this issue in over a year, we’re closing it as Timed out.
If you feel that the bug is still relevant to your needs, please leave a comment and we'll reassess it.

Kind regards,
Dong Hoang
JIRA Software

Affects also JIRA Agile 6.6.51. Workaround is to place cursor on the upper or lower half of the issue card before dragging. It is still annoying.

It seems this bug only happens if the user logged-in does not has project admin permission.

Can we have a time frame on when will this ticket get a fix as it is affecting our company users very much!

This is a problem we're having. I believe the issue is a UI bug. The problem is fact that the user is prompted (blue drop zone areas (status) appear) when a card is dragged from one column to another which happen to have multiple statuses. The issue is that while dragging the issue to hover over whichever status within the next column, the vertical movement is restricted and not functioning correctly. I can not move the mouse vertically high or low enough to cover all available statuses to drop the dragged card in. Also, if there's only one task in a story in one column, and the next column have 4 or more statuses, the board's UI row won't expand enough to show all available statuses. Only the first two show upon dragging a card over, and the rest of dotted blue status areas are cut off. I think the resolution should be that the board rows should expand enough to show all statuses within the next column over.

Actually, you can have more than one subtask. The problem is seen when there is just one "row" of subtasks, regardless of how many subtasks there are. If your board had four columns you would see the problem if there were four subtasks, one in each column.