When you live in a community property state such as Texas that recognizes the marriage, special rules apply to the calculation of an injured spouse refund.
Please see Line 5a in the Instructions for Form 8379 for the best available guidance.
You'll notice that in the chart within the Line 5a text, there's guidance regarding the amount of an overpayment from a joint tax return that the IRS may offset against a spouse's separate tax liability specific to Texas. See Revenue Ruling 2004-74.
For additional information, also see the TurboTax Help article Married filing separately in community property states and IRS Publication 555, Community Property.