Press the SAUTE button. When the pot is hot, add in the ground beef, onions, and green pepper.
Cook until beef is no longer pink. If desired, drain grease.
Add in corn, tomato sauce, diced tomatoes, brown sugar, soy sauce, Worcestershire sauce, salt, pepper, and garlic powder.
Add uncooked macaroni noodles on top, then pour beef broth on top of macaroni. DO NOT STIR, but press down the macaroni so that it's all covered in liquid as much as possible.
Place the lid on top of the Instant Pot and turn the knob to SEALING (not venting).
Press the MANUAL or PRESSURE COOK button and set the timer for 4 minutes.
Do a QUICK RELEASE of the pressure when the timer is done (move the knob to VENTING to let out all the steam).
Remove the lid and stir everything together.
If desired, you can serve this with shredded cheddar cheese on top.
Notes
The noodles will continue to absorb the liquid as it sits. If you reheat this for the next day, you might want to add a little liquid to it.