Hi, can somebody tell me how to handle pasted objects in Inkscape please?

I thought it would be straightforward, but apparently it's not.

I've imported a drawing onto a root layer, and I then want to stamp objects around the border, with all the objects on a 'border' layer.

I've created a new layer called border and copied and pasted an object onto the border.
I've then copied the object, pasted it and then tried to move it to place it where I want it.

Logical so far...

However, I find that the object apparently selects ok, but when I move the mouse to change the position of the selected object, instead of moving the object the layer suddenly changes back to 'root' and the mouse loses its grip on the object.

Why is the software changing layers instead of moving the selected object?

I've tried clicking the padlock to 'lock current layer', but it doesn't prevent the layer change when I try to move an object, or sometimes when I try to select it.

It's SO frustrating!