Hello there, sometimes it is really hard to id hybrids. Unfortunately I do not have that plant either so I have no basis for id. Oftentimes I have to wait one full year and photograph some of my succulents in each season to see how it truly looks like, especially if it manages to bloom. Give it time to see if the other more prominent features of Graptopetalum bellium shows better. I have read summer is its active growing period. I would suggest for now keep the id as to what you got when you purchased it. If the other characteristics do not show up later on, then you can truly say it was mislabled.
Variances in the plants growing pattern especially if they were grown more in an indoor setting than in a natural outdoor set-up affects the plants appearance, or if they were semi-dormant makes them look different too, so got to be patient for now and wait a bit.