When removing the last item in the cart the Undo message will not appear. Instead the undo message will appear next time you visit another product. I’m using a Bricks Template to display an empty cart message. When not using any Bricks Template the Undo message will appear normally. So it seems to have something to do with the Template.
Ah, I did not know about this. I tried it out and it works fine now. The success message is now displayed in the empty cart after removing the last item. Thanks!