There are a few reasons why an Instant Pot roast might come out tough. One possibility is that the meat was not properly browned before it was pressure cooked. Browning the meat helps to seal in the juices, which keeps the roast moist and tender. Another possibility is that the roast was overcooked. Instant Pot roasts should be cooked for a shorter time than traditional oven-roasted meats. If the roast is overcooked, it will be tough and dry. Finally, it is important to let the roast rest for at least 10 minutes after cooking before slicing it. This allows the juices to redistribute throughout the meat, making it a more flavorful and tender pork roast.