There is unlikely to be an error in the TT software. But it is likely that you made an entry error, that resulted in an erroneous return.
The IRS notice should have provided more detail on what the change(s) is. There is usually an attachment with details
For example, "IRS received information from a third-party" usually mean the IRS changed your reported/taxable income, which only incidentally changed the amount of the Dependent care credit (DCC) in addition to other changes.
For more info, see https://ttlc.intuit.com/community/irs/help/i-got-a-letter-or-notice-from-the-irs/00/27100
and
https://ttlc.intuit.com/community/irs/help/how-do-i-respond-to-an-irs-notice-and-what-if-they-want-t...
