If your IRS-issued tax refund comes in around $35 or $40 less than the amount shown in TurboTax, it's probably because you used the Pay With My Refund service to pay your TurboTax fees. There's a separate processing fee for this service, which is deducted from your federal refund in addition to your TurboTax fees.
Please see this TurboTax FAQ on why your direct-deposit refund or check may be lower than what you expected: https://ttlc.intuit.com/community/refunds/help/why-is-my-direct-deposited-refund-or-check-lower-than-the-amount-in-turbotax/00/25594.The IRS will send you a letter of explanation when your refund is less than you expected you can also get this information by looking up your refund at the IRS Where's My Refund page.
If this is for a state refund please contact your state Department of Revenue.