I think that there is an issue if you download data between 1/1/2020-12/31/2020. The data may not take care of your previous deferred loss (wash sale). Because I saw the csv total of proceeds and cost basis not tie with 1099B total of proceeds and cost basis. So even they can convert the file, your numbers might not be good enough. Since IRS will check the totals against your 1099B.
