Turn the Instant Pot to Saute mode on Normal heat. Add the bacon pieces and cook for 4 to 5 minutes, stirring occasionally, until the bacon is crispy and the fat has rendered out. Use a slotted spoon to transfer the bacon to a paper towel-lined plate, leaving the drippings in the pot.

Add the diced onion to the bacon fat in the pot. Saute for 3 to 4 minutes until the onion is soft and translucent. Add the minced garlic and stir for about 30 seconds until fragrant. Press Cancel to turn off the Saute function.

Add the cubed potatoes, frozen corn, chicken broth, Old Bay seasoning, smoked paprika, salt, and pepper to the pot. Stir to combine. Secure the lid and set the valve to sealing. Pressure cook on high for 5 minutes.

When the timer finishes, do a quick release by carefully turning the valve to venting. Once the pin drops and all pressure is released, open the lid. The potatoes should be fork-tender. If you want a thicker chowder, whisk the cornstarch and cold water together in a small bowl until smooth, then stir the slurry into the hot soup.

Switch the Instant Pot back to Saute mode on Normal heat. Pour in the heavy cream and stir to combine. When the soup is gently simmering, add the shrimp in a single layer across the surface. Cook for 3 to 4 minutes, stirring once or twice, until the shrimp are pink and curled. Pull one out and cut it in half if you are unsure. It should be opaque all the way through with no grey translucent spots. Do not overcook them.

Press Cancel and taste the chowder. Add more salt, pepper, or Old Bay as needed. Ladle into bowls and top with the reserved crispy bacon and a sprinkle of fresh chives or sliced green onion.