When I select part of an image and copy it (Ctrl J) to a new layer, it appears in the new layer with a white background instead of a transparent one. It used to provide a transparent background. I must have changed something, but I don't know what. I am using Elements 14.
I have discovered the problem. I went into Edit Preferences Transparency and set the Grid SIze to small . It had been set to None - which is effectively white. I don't know how that happened, but it is sorted now. Thanks.