Remove the membrane from the back of the ribs (this helps them get super tender). Cut each rack in half to fit in your Instant Pot.
Mix together brown sugar, paprika, garlic powder, onion powder, salt, and pepper. Rub this spice mixture all over both sides of the ribs.
Pour beef broth into the Instant Pot and place the trivet inside. Stand the rib pieces upright against the sides of the pot (they'll look like they're hugging the edge).
Close the lid, set valve to sealing, and cook on high pressure for 25 minutes. Allow natural pressure release for 10 minutes, then quick release remaining pressure.
Carefully remove ribs and place on a foil-lined baking sheet. Brush generously with BBQ sauce.
Broil in the oven for 3-5 minutes until the sauce is caramelized and bubbly. Watch them closely so they don't burn!
Let rest for 5 minutes, then cut into individual ribs and serve with extra BBQ sauce on the side.