Keys and layers?

While working on a complex problem I’ve tried moving objects I’m working on to a different layer, hoping to get that bit of animation sorted, then move it back to the first layer.

When I try this all the dope and graph information buggers off! I go back to layer one, still no animation data. Only when I move the objects back to layer 1 can I see the animation keys. Are keys locked to the layer they’re created on?

Or - am I, as is usually the case - missing something?

Are keys locked to the layer they’re created on?
No

If you move the object to another layer and that layer is not currently enabled in the viewport, on the graph editor enable the button with the ghost icon to include channels for objects that are not visible