Turn Instant pot to saute.
Season chicken breasts on both sides with paprika, salt and pepper.
Add 1 tablespoon olive oil to the hot instant pot.
Add chicken breasts and cook for 2 minutes on each side, until browned, but not cooked through. Remove to a plate.
Add butter and onion to the pot and sauté for 2 minutes.
Add chicken broth, (scraping the bottom of the pot to deglaze it), seasonings, milk, pasta, and chicken breasts back to pot.
Close IP lid and turn release valve to sealed. Cook on manual (high pressure) for 5 minutes.
When the timer beeps, do a controlled quick release, to release the pressure. (Turn the valve but if any liquid sprays close it again and try again in a few seconds.)
Carefully open lid. Remove chicken to a plate and tent with foil. (Don't skip this step. The chicken will continue to cook under the foil).
Stir in cream cheese, stirring gently until it's melted and the sauce is smooth.
Stir in parmesan cheese, sun dried tomatoes and spinach. Season with salt and pepper, to taste.
Chop chicken and return to pot.
Sauce will thicken as it cools. Serve warm, garnished with extra parmesan cheese, if desired.