Heat the olive oil on the 'sauté' setting. Once hot, add the onion and carrot, season with salt and pepper. Cook for 4 to 5 minutes, stirring frequently, until onions are translucent and the carrots are soft. Carefully remove the vegetables from the pot to a separate bowl.
Make the roux by melting the butter on the 'sauté' setting. Sprinkle the flour over the melted butter, stirring to form a paste. Continue to stir while paste thins out and cook until it because a light tan color, about 2 minutes.
Using a whisk to avoid clumping, slowly add about 1/2 cup of the chicken stock while whisking continuously. Repeat until the roux is fully incorporated into the stock and add the remaining stock and heavy cream. (See notes for what to do if your broth clumps.)
Add the corn, wild rice and chicken. Close the Instant Pot and make sure the valve is on the 'sealing' setting. Cook for 20 minutes on high pressure or using the 'stew' option depending on your model.
Once the Instant Pot is done cooking, manually release the pressure by pushing the valve to 'venting' - watch out for escaping steam! Once the red button goes down, remove the lid.
Transfer the chicken to a separate plate and shred using two forks. While you are pulling the chicken, put the Instant Pot on the 'sauté' setting for normal heat to thicken the roux. Transfer the pulled chicken and any juices back to the soup and season with salt and pepper to taste.