Set the Instant Pot to saute mode and add vegetable oil. Add the onion and cook for 5 minutes, stirring occasionally. Add the minced garlic and saute for one minute.
Turn off the Instant Pot and add one cup of chicken broth. Deglaze the pot by scraping the bottom of the pan to remove stuck-on onion and garlic. Season with Cajun seasoning and parsley.
Add the beans, bacon, diced ham, water, and remaining chicken broth. Stir to combine.
Place the lid on the Instant Pot and seal the vent. Set the Instant Pot to pressure cook for 35 minutes.
When the cook time is up, allow the Instant Pot to naturally release for 10 minutes, then do a quick release to remove remaining pressure. Stir soup before serving.
Note: To thicken the soup, mash some of the beans using a potato masher. Stir to combine.
