This seems like a silly question, but how do you move pieces in the Creation Kit render window?

All the tutorials and videos say to, or show that you just click and drag with the left mouse button. Not in mine!

I select the chest and it is outlined in red, green and blue; the arrow changes to the arrowed cross shape when I hover over it, but when I try to click and drag nothing happens. It makes no difference if snap to grid/angle is on or off.

All the other buttons work: such as pressing Y to cycle camera views or SHIFT F to focus. Using the arrow keys will move the item by large stepped increments.

if I press 'E' I get some arrow movement gizmo appear and when I hover over each axis' arrow it changes to a yellow colour and if I click it, it selects that axis' control arrow which stays yellow, but when I try to click and drag it... nothing.

This doesn't make any sense, and nothing I've googled seems to show anyone else ever having this problem.

Unless I want a dungeon with one floor piece, it doesn't look like I'm going to get past duplicating the first piece in the first tutorial...