Saute bacon in a large skillet over medium heat or use the Instant Pot saute function. Season beef with a bit of salt (the bacon is fairly salty), and black pepper. Saute beef until just browned, the beef will not be fully cooked at this point.
If you are using the Instant Pot to saute, you will need to saute the meat in batches. As you brown the meat place it into a shallow dish. Once all meat is browned sprinkle it with the flour, and stir to coat the beef. Deglaze the pan with some of the Guinness. Scrape the pan to pull up the browned bits. Place the liquid into the Instant Pot. Add flour coated beef to the Instant Pot. Add the remaining stout, chicken broth, Worcestershire sauce, soy sauce, 1/4 of the chopped onions, bay leaves, and 1/4 of the chopped carrots to the Instant Pot.
Cook for 25 minutes on the manual setting. Perform a quick release when the 25 is done. Add all remaining vegetables and garlic to the pot and then cook on the manual setting for 4 minutes. Perform a quick release when the soup is done. If you are happy with the thickness of the soup, serve immediately. If not add a mixture of 2 tablespoons of cornstarch mixed with 2 tablespoons of water and stir into the hot stew. Remove bay leaves before serving. If the amount of fat of in stew concerns you, cool the soup in the refrigerator and remove the fat layer once the soup has cooled.