Can't get all OO to OF import methods to work as advertised

Following on from a suggestion in the forum, I’m creating all of my various projects in OO, and then exporting the relevant bits to OF once the project are active (ie close or have due dates).
There are 3 methods in the OF docs -

  1. directly open an OO doc. This is no good for my purposes as I don’t want the whole doc, just particular projects.
  2. Drag and drop. I can’t get this to work at all. I select a project (ie a Level 1 item) in the main OO window. When I click, hold and drag, all that happens is that more lines get selected. Similarly if I click/hold/drag in the Contents pane. Could this be because of a system setting?

Copy & paste. I tried selecting an OF item in the Projects panel (doesn’t work) and a Project name in the main pane (with no Projects being in Focus(. That works, though what happens is a slight surprise - the copied info creates a new Project rather than being copied into the selected existing project (which makes sense, except that it seems an odd way of going about it.) If I’ve focussed on a project, and select the Level 1 line, then the data gets pasted into that project, which will work as long as I’ve selected everything below the first (most outdented) line in OO.
In the end it seemed safest to paste a full project into the Inbox and then drag/drop it onto the Projects tab.

So it’s mostly working, and it would be useful to know why drag/drop isn’t working for me.