The problem is likely that you're adding items that do not already exist in the sku grid database (most of them) -- and you don't have any credits in your skugrid account. So what happens is, some of the items you're adding have already been added to sku grid by other users, therefore, skugrid is able to see the data and make it show up on the screen. However, for the items that do not currently exist in sku grids database, skugrid is not going to go and check the items because you have no credits in your account. Therefore, they continue to read as vendor. You need to add credits to your account otherwise, sku grid does not supplier checking either as that also costs credits. 

Please see videos below. 

How to Add 7 Day Test Drive for $0.01 - 

How to Add a Paid Subscription -