I have a sprint (Sprint2) which there is still 24 hours free capacity.

However, another issue which only has 8 hours is scheduled to next sprint (Sprint3) instead of Sprint2.

Here is the information for these 2 issue, wmam-316 is the one in Sprint2, wmam-317 is the one in Sprint3 and can't be scheduled to Sprint2. There is no dependency between these 2.
Anyone has any clue why does this happen?