Place corn, potatoes, onion, and broth in the pressure cooker. Cover and Select "Soup" mode (30min).When cooking is complete use a natural release to depressurize. Carefully turn the vent to “Venting,” just to release any extra pressure that might still be in there. Then remove the lid.
Select "Saute" mode and adjust to low. Stir in butter, brandy, and heavy cream. Allow soup to cool slightly, then transfer mixture to a blender or food processor; cover and puree in batches until smooth. Return to cooker. Taste and adjust seasoning adding sugar, salt and/or black pepper to your liking. NOTE: if the bisque is too thick to your taste you can add hot water to reach desired consistency.
OPTIONAL: For thin and extra smooth texture place a fine sieve over a medium-size bowl and strain mixture, pressing on solids with the back of a spoon. Discard solids.
Serve immediately topped with crisp bacon and sliced green onions, if desired, or keep warm, covered, on warm or low up to 2 hours.