Turn Instant Pot to saute function and allow to heat. Add 2 tbsp olive oil, then chopped green peppers, onion, and minced garlic. Saute until the onions and green peppers soften (approx 4 minutes).
Pour approximately 1/4 cup of the chicken broth in the Instant Pot, then use a wooden spoon to scrape the brown bits stuck to the Instant Pot's bottom. It is important to deglaze the pan in this step so that it will come to pressure correctly. Those bits are also incredibly flavorful.
Add all of the other ingredients except the ranch seasoning and cream cheese, then place the lid on the Instant Pot to seal.
Turn on high pressure for 14 minutes, then allow the Instant Pot to come to pressure and begin cooking.
Once the 14 minutes of pressure cooking has completed, allow a 5-minute natural pressure release, then do a QR (quick pressure release) by turning the pressure valve to release the steam. I always cover the valve with a kitchen towel to avoid it spraying on my cabinets.
Once all the steam has released, and the pin has dropped, remove the lid.
Take out the chicken breasts, place them on a cutting board or plate, shred them with two forks, then return the chicken to the Instant Pot. I prefer larger chunks of chicken in this recipe.
Turn the Instant Pot to the saute function and add the ranch seasoning. Make sure the cream cheese is softened, then scoop out about a cup of the soup to add to the softened cream cheese. To best incorporate the cream cheese in the soup, I use either an immersion blender or whisk to mix it into the cup of soup first, then pour the entire mixture back into the instant pot. Stir to combine.
Boil for approx 4 minutes on saute function, then add salt and pepper to taste.