Heat oil in Instant Pot on Sauté setting. Add chopped onion and sauté until it begins to soften, 1-2 mins.
Add squash, carrots, broth, cider, curry powder, cinnamon, and nutmeg.
Cook on manual high pressure for 6 minutes.
Once done cooking, allow the pressure to release naturally for 10 mins, then quick release the remaining pressure (you can quick release if in a hurry).
Use an immersion blender or pour mixture into a blender, blend until smooth.
Add pumpkin, butter, cream cheese, and brown sugar; blend until smooth. Add salt to taste. (If using a blender, you may need to pour some of the mixture back into the Instant Pot so you have room to add the additional ingredients, then stir it all together in the Instant Pot to combine.)
Garnish with cooked pumpkin seeds, if desired.
Notes
Make sure you do NOT use apple cider vinegar... it will taste horrible in this soup!