Crust: Combine ground graham crackers, melted butter, flour, brown sugar, and salt. Press firmly into the bottom and sides of a parchment-lined 7-inch springform pan. Freeze for 10 minutes.
Cream Base: Beat room-temperature cream cheese, sugar, and salt on low speed until smooth.
Add Liquids: Mix in sour cream, vanilla extract, and flour on low until combined.
Add Eggs: Gently stir in eggs one at a time on low speed just until incorporated. Pour into chilled crust.
Wrap & Cook: Cover pan tightly with aluminum foil. Pour 1.5 cups of water into the Instant Pot, place pan on the trivet, and lock lid. Pressure cook on High for 35 minutes.
Release & Set: Allow a 18-minute natural pressure release, then vent remaining steam. Uncover, cool on a rack, and chill in the fridge for at least 6 hours before serving.