There could be several reasons: 1. Overcrowding the skillet can prevent proper air circulation and hinder browning. Make sure to cook the hash browns in batches, leaving enough space between each patty to ensure they crisp up evenly. 2. Heating the skillet to the right temperature is also important. Underheated skillet can lead to undercooked and soggy hash browns. Make sure the skillet is preheated over medium-high heat before adding the hash browns. Adjust the heat as needed during cooking to maintain a consistent temperature. 3. Using too little oil or not distributing it evenly in the skillet can result in uneven browning and a lack of crispiness. Ensure the skillet is adequately greased with oil before adding the hash browns, and add more oil if needed.