I am tearing my hair out here-- I am unable to drag and drop items in my spreadsheet. I can drag an item to be a subcategory of an existing item, but the described behavior-- drag an item BETWEEN two items, and when the blue line appears drop it and it will be between the two items never happens. Either I get a blue box that surround the whole spreadsheet and the item stays in place, or I get a blue box around an item and the item I’m trying to move will become a subcategory. I feel very dimwitted. What am I doing wrong? 
Just to check, you haven’t reordered your spreadsheet by a column other than the chronological order (the # sign column)? Once the spreadsheet is reordered by something other than this, you can’t reorder it by drag and drop. However there should be a message appearing when you try to drag and drop that says “Sort by # to allow row-reordering”. Does this happen for you at all?
I’m having the same problem.
Hi! I’m coming back to this thread late, because I was having the same problem again, and checked the thread for an answer. I was unable to drag and drop, but then sorted by number, as you suggest, and it worked as expected. Thank you!
I did not get any kind of message that said “sort by number to allow row-reordering.” I was able to drag and drop events on TOP of other events, making them sub-events, so it would not have occurred to me to sort by number.
