Set Instant Pot to the sauté function, and add olive oil, carrots, onion, and garlic. Cook for 2 minutes, until beginning to soften. Add potatoes, 1 cup of the broth, parsley, salt, and pepper. Stir, cover, seal, and cook on manual/high pressure for 5 minutes.
Meanwhile, combine the remaining 2 cups broth, milk, cream cheese, and flour in a blender. Process until smooth.
When the 5 minutes is up, use the Instant Pot’s quick release function to vent steam. Open the lid, return Instant Pot to the sauté function, and stir in the mixture from the blender. Continue cooking, stirring frequently, until the soup simmers and thickens.
Add cheese and stir until melted. Serve immediately, or switch to the keep warm setting for up to an hour, stirring occasionally. Serve with extra cheese, bacon, chives, green onions, or other toppings as desired.