Did the IRS or state reduce your refund? If you owed back taxes or child support, they can offset your refund. TurboTax never knows about offsets to your refund. If the IRS or your state reduces your refund they send you a letter a few weeks later to explain why your refund was reduced.
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