With Instant Pot on sear, cook diced bacon until just crispy. Remove to a paper towel to drain.
In the grease rendered from the bacon cook the leeks and garlic for 2 to 3 minutes, until translucent.
Add potatoes and chicken broth.
Place lid on Instant Pot and using high pressure cook for 6 minutes. Let natural release for 10 minutes, then quick release any remaining pressure.
Remove half of the potato mixture to a large bowl. Using an immersion blender*, puree the potato mixture remaining in the pot.
Return the mixture from the large bowl, add 1/2 cup half and half, and white cheddar cheese, stirring to mix and melt cheese.
Add the remaining 1/2 cup half and half and stir.

*If you do not have an immersion blender, place the half of the potato mixture into a stand blender and puree, returning the mixture and follow the directions as stated.

To serve place soup in bowl and garnish with bacon, extra cheese, and chives.