Turn instant pot to sauté. While Instant Pot is heating in a medium size bowl mix together the ketchup, brown sugar, tomato paste, mustard, vinegar, chili powder, and Worcestershire sauce; set aside.
Lightly spray the instant pot with cooking spray, add the burger and garlic, and cook until burger is browned, breaking it up as it cooks; drain excess fat if needed. Mix in the onion, pepper, and celery and cook for about 2 minutes. Mix in the beef broth and tomato sauce mixture, seal the pot, and pressure cook on manual high pressure for 7 minutes; and then quickly release the pressure.
Mix the water and cornstarch together and stir the cornstarch mixture into the Instant Pot, set to sauté, and cook until mixture thickens. (about 2 minutes)