Add the potato chunks and eggs to the Instant Pot insert. Pour in 1 cup of water.
Secure the lid and set the valve to sealing. Cook on high pressure for 4 minutes.
Once cooking is complete, let the pressure release naturally for 5 minutes, then quick release any remaining pressure.
Carefully remove the eggs and place them in a bowl of ice water to cool. Transfer the potatoes to a large mixing bowl.
Peel the cooled eggs and chop them into small pieces. Add them to the bowl with the potatoes.
In a small bowl, whisk together mayonnaise, sour cream, mustard, apple cider vinegar, salt, and pepper until smooth.
Pour the dressing over the potatoes and eggs. Add celery, red onion, dill, and chives.
Gently fold everything together until well combined. Taste and adjust seasoning if needed.
Cover and refrigerate for at least 1 hour to let flavors meld. Garnish with paprika before serving if desired.
