Add pasta, chicken broth, water, butter, salt, garlic powder, onion powder, mustard powder and black pepper to the inner pot of the Instant Pot. Press the pasta gently with a spoon to submerge it, but don't mix it.
Secure the lid and set the valve to sealing. Manually set to pressure cook for 4 minutes.
Once the timer goes off and beeps, release pressure immediately by carefully turning the valve from sealing to venting. Let all the pressure release and open the lid.
You'll see a little residual liquid in the pot which is normal. Mix in heavy cream and cheese in batches till you get a smooth, creamy sauce. Serve immediately.