Conversion of part of non-RMD 2020 regular IRA Distribution to Roth IRA

In 2020 I converted part of my IRA withdrawals to a Roth IRA contribution.  TurboTax is computing part of that conversion as being nontaxable.   It should all be taxable.  The IRS rejected my return, probably because of this error.  I think this is a bust in the TurboTax program.  Has anyone else experienced this?