Actually, the confusion between the two can be worse than this! Wepwawet wasn't depicted as grey-headed by the Ancient Egyptians (it's a modern myth/misunderstanding), he's as much a black jackal as Anubis! The only way to really tell them apart in this particular form is by the accompanying inscription.
Poor guy, he really does get conflated with Anubis a lot even though he's definitely his own separate (and awesome) god.
I need to spruce up on my knowledge of the gods. I have not heard of "Not Anubis" before. XD
I think if I were a god or goddess, I'd be pretty annoyed if people kept mistaking me for someone else. I know how it feels. People are stupid and always think I'm someone else because I'm an Asian girl, and they can't tell Asians apart. The girls who they mistake me for look nothing like me. In fact, some of them are much too old, too young, or don't even have a similar haircut as me.