mac catalyst app not loading textures from atlas

Hi All,

I am converting an iPad/iPhone/AppleTV app to Mac Catalyst. All seemed to go well until I access images from my image atlas.

I have this set of image files:-
bike@2x
bike@2x~ipad
bike~ipad

When I load the texture I get:-
<SKTexture> 'MissingResource.png' (128 x 128)

How do I solve this ???

Thanks in advance.

Steve