That the IRS said TurboTax makes calculated my refund

TurboTax never knows about back taxes or child support you owed.  Only the IRS and/or the state knows about that, and they can offset your refund for those.  They send you a letter afterward.   The IRS often uses the generic term "calculation error" to refer to mistakes they found on your tax return.  TurboTax does not receive any information from the IRS after you file your return.

Reduced Refund      https://www.irs.gov/taxtopics/tc203

 NOTE: You can contact the IRS Treasury Offset Program Call Center at 1-800-304-3107 to ask if they have an offset for you on file. TurboTax would not have that information.

https://turbotax.intuit.com/tax-tips/tax-payments/who-can-garnish-an-income-tax-refund/L7cPPzDyc

I RECEIVED A LETTER FROM THE IRS/STATE

TurboTax does not receive any information from the IRS or your state after your return was filed, so no one at TurboTax knows about a letter you received from the IRS or the state.

https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-audit/turbotax-audit-support/L6AcMoNFD_US_en_US?uid=m5z7by9u

https://ttlc.intuit.com/turbotax-support/en-us/help-article/internal-revenue-service/got-cp2000-notice-irs/L7Da6em2t_US_en_US?uid=m4of6ngd