IRA - Roth conversion not handled correctly by TurboTax 2021

As in past years, my wife and I each make $7.000 non-deductible contributions to our traditional IRAs and then convert the amounts to Roth IRAs.  This doesn't cause a tax impact because they're all after-tax dollars, and TT has handled this fine.  However, this year TT is doing something strange: of my $7k it's saying that $6.863 of it is taxable, but it doesn't explain where that number is coming from, and I can't figure out how to fix it. I'm looking through the IRA Information Worksheet, which is the source of the data, and my wife's basis carryover as of 12/31/2021 is correctly shown as $21,000 but mine is incorrectly shown as $20,863.  It seems clear that the two errors are related since both incorrect numbers end in 863.

 

Given that it's still early in tax season, I'm wondering if this is a bug someone else has seen. We're using the downloaded version of TT.

Thanks,

Scott