Set your Instant Pot to sauté mode and cook the bacon pieces until they're golden and crispy, about 8-10 minutes, stirring occasionally. Remove the bacon with a slotted spoon and set aside, leaving about 2 tablespoons of bacon fat in the pot—this is your flavor foundation. Add the diced onion and bell pepper to the pot and sauté for 2 minutes, stirring occasionally, until they begin to soften. Stir in the minced garlic and fresh thyme, cooking for another 30 seconds just until fragrant. This aromatic base will infuse the entire chowder with deep, savory flavor.
Pour in the chicken broth, scraping the bottom of the pot to release any flavorful browned bits. Add the peeled and cubed potatoes and most of the corn (reserve about 1/2 cup for later), along with about half of the cooked bacon. Season generously with salt, cracked black pepper, and smoked paprika, stirring well to combine. Lock the lid in place and set the Instant Pot to HIGH pressure for 6 minutes. I like to add the smoked paprika at this stage because cooking under pressure helps meld it into the broth rather than having it sit on top.
Once the pressure cooking is complete, carefully perform a quick release by moving the valve to the venting position. Once all steam has escaped, remove the lid and switch the pot back to sauté mode. Add the reserved corn (about 1/2 cup) to the pot—adding it now keeps the corn kernels fresher and prevents them from becoming mushy during the long pressure cooking.
While the pot is heating, whisk together the room-temperature half and half with the all-purpose flour in a separate bowl until smooth and lump-free—this prevents the cream from curdling when it hits the hot broth. Once the soup is simmering gently, slowly pour the flour-cream mixture into the pot while stirring constantly to ensure it incorporates smoothly and thickens evenly. Let the soup simmer for about 4 minutes, stirring occasionally, until it reaches a creamy, velvety consistency. Stir in the lemon juice at the end for brightness.
Taste the chowder and adjust seasoning if needed. Ladle the soup into bowls and top each serving with the remaining cooked bacon pieces and a generous sprinkle of fresh chopped parsley for color and freshness.