In a small bowl, mix together paprika, mustard, garlic powder, brown sugar, kosher salt and pepper. Place pork in a glass baking dish and sprinkle over dry rub and pat into meat on all sides. Cover with plastic wrap and place in refrigerator for 1 hour.
Remove pork from glass container and place in Instant Pot. Set to pressure cook - high. Set time to 15 minutes per pound of pork. When timer sounds, turn Instant Pot off and allow steam to release naturally, approximately 20 minutes. When valve drops, remove lid and carefully remove pork from pot. Shred meat with two forks.
Ultimate Nachos
Heat oven to 350 degrees. Using a large cast iron skillet or oven proof pan, layer on tortilla chips covering bottom. Add a layer of pulled pork then sprinkle with cheddar and Monterrey jack cheese. Repeat with another layer. Place skillet in oven and cook for 10 minutes or until cheese has melted and chips are hot.
Remove skillet from oven. Layer on tomatoes, beans, corn, avocado and jalapenos. Drizzle on BBQ sauce and sour cream. Top with additional pulled pork and cheese.