Figma default variant


When i create and instance of default variant like following

figma.importComponentSetByKeyAsync(key).then((res) => {
                const variant = res.defaultVariant as ComponentNode;
                var comp = variant.createInstance();

This does not create the exact component of the default variant, it creates different component instance every time by defaultVariant.

What will be the solution for the same?

If i click on plugin button thumbnail then it create buttonwith heart and if another user will create from his account then it create simple button from component set.

What could be a reason behind it?

Is there any key issue that key varying every time for new user in library or be the same for everyone?