I have imported 1099 Bs for three accounts with Fidelity (National Financial Services). Only two show up during review. When I add the missing one again, another is gone

Only two 1099 Bs show up for review.  If I reimport the missing 1099, one of the other two then disappears from the review page.  There is no way to tell if the missing 1099 information is still present or whether it has been deleted.  Further, I can't tell if the data is duplicated once I reimport.  Every time I go through the process the tax due decreases.