Hi,

There are no hidden tabs, but check if you aren't seeing the result of ContainerNode.Margin and CaptionHeight properties. Margin specifies how much space the container should leave around its children when auto-growing. CaptionHeight will be reserved on container's top side too, even if you are using a custom template that hides the caption bar. So in your case you might try setting both to 0.

Also note that child node's coordinates you specify via Bounds are relative to the diagram anyway, and not local for the container. We could add some kind of LocalBounds property if you prefer setting local coordinates for the container.

Regards,
Slavcho
Mindfusion