Project folders not closing automatically

I have several project folders set up to represent my roles in life. As part of my weekly review I drag new projects that I have accumulated during the week into the appropriate folder. In OF1 this would cause the folder to spring open and then when I release the drag the folder would automatically close.

In OF2, the same drag causes the folder to open but then on releasing the drag the folder remains open. Is there any way to have this changed so it replicates the OF1 behaviour?