1.17^7= 3 so it is clear that it is 7GR if you look at damage only 0% compared to 200%.
Because I dont play Barb I did not know that legendary power “Rend can now stack up to 2 times on an enemy” was on the old version of belt.
7 GR lvl nerf is definitely too much it is better to keep it like this than do 7 LVL GR nerf. I would prefer middle but that is other topic.
Now I think it must be unintended bug with Diablo 3 build for consoles at Blizzcon.