Importing last year's tax return

I've used Turbotax for over 20 years with little or no problem.  This year when I imported last year's income tax (2018) information I found the information imported is inaccurate.  For example the amount of interest and dividends shown on the imported tax information is substantially less than the amounts shown on last year's tax returns.  I realize I will be changing those numbers to reflect the amounts for 2019 but when I observe consistently wrong information being imported it makes me very nervous about why that imported information is so inaccurate.  Anybody have any thoughts about why this happened?