TurboTax 2016 1099-B Import Error/Bug?

I do my taxes with TT every year. I did my 2016 return using TT Home & Business. I just got a form CP2000 from the IRS saying there's a discrepancy and I owe them several thousand dollars.

 

I reviewed what they're talking about and it's regarding a form 1099-B from Vanguard. I believe this was imported electronically. I have the form open in TT but not sure how to tell if it was pulled in that way or I entered it manually. I tend to do the import electronically. Anyway, there are two entries on the paper form which we just downloaded and printed from Vanguard. Both entries are for the exchange of funds in a retirement account.

 

I can see the 1099-B and first transaction in TurboTax, but don't see the second transaction in that 1099-B anywhere in TT. Is it possible TT didn't pull the second transaction in? Was there a bug like this or something at the time?

 

To make it more confusing, the IRS form seems to indicate they see it somewhere in my return, except the cost basis was used as the proceeds amount and somehow "reported to them by third parties" they have the cost basis as the proceeds. I don't find either number in my form (printing all forms to PDF and searching, don't see a way to search by an amount in TT).