Yes, there are ways. The best way is to compare a original and the (potentially) fake cart side by side. Theoretically it should be a defintive proof to compare the boards, but most people do not want to open their ds games.
Tbh, I am not sure if that is the problem because I don't use any save manager. If the cart is just not supported yet by any software, then you could also dump the save with a special usb device.