Investors & landlords

Company was BIOVERATIV INC. Oldest online price history found is $44.42 on 1/18/2017. I don't see it on any of my statements, which seems odd; I don't know how or when I acquired that stock! Anyway, it was $105 on 3/8/2018 when it merged. I had 230 shares. The cash did show up as a purchase in my brokerage account under "Insured Deposit Account". Nothing showed up in the 1099B. There was an entry under "UNDETERMINED TERM TRANSACTIONS FOR NONCOVERED TAX LOTS" with no date acquired or basis that was not sent to the IRS. Hence my problem since I didn't know what to do at the time and did not include that on my tax return! Well, now I need to fix it.