The Instant Pot needs to have a lot of liquid. The more liquid it has, the less likely it is to burn. This means you should not skip the chicken broth because the added liquid helps prevent you from getting the burn notice. If you do not want to add chicken broth because of the sodium level, you can use a reduced sodium variety or use water instead (though you might notice a bit less flavor with water). When you add in the chicken broth, make sure you use a sturdy spoon to mix the beef and broth. Use the spoon to scrape the bottom of the pot to remove any stuck on bits. If too much beef is stuck to the pot, you could get the burn notice.