When you save or print a copy of the return Including all worksheets, you should find the Sch D computation included in the worksheets.
IRS did have an error in their tax computation with capital gains on returns that were filed before mid March resulting in letters being sent out recently with the adjustment. Mid-March IRS informed tax software providers of their error and the tax programs were able to be updated for the correct computation, so this may be you situation.
https://www.irs.gov/forms-pubs/error-in-tax-calculation-in-schedule-d-tax-worksheet-form-1040
Unfortunately I did not save a copy when I submitted. The copy I have I downloaded from TurboTax which does not seem to have the 1099B.
Would the IRS computation error be also realized on my 2017 filing?
A 1099-B is a form you get from a financial institution reporting the sale of securities. A 1099-B is not part of a tax return - only the information that you enter about the securities from the 1099-B goes on a Schedule D which is part of the tax return.
No, that IRS error was for 2018, your post didn't specify which year you were referring to.
You'll want to look for Sch D and the 8949 to see if 1099B stock transactions were included on the 2017 return.
Does your pdf have all the worksheets? You need to see schedule D and probably forms 8949 and 8453
Log back in your TurboTax account and "add a state" to open the return back up (you are not really adding a state, just to open it back up), then
Click on Tax Tools on the left side of the online program screen.
Then click on Print Center.
Then click on Print, save or preview this year's return. Choose the option Include government and TurboTax worksheets