Heat a skillet over medium-high heat. Add the ground beef and cook until evenly browned, breaking it into small pieces with a spoon. Cook until no pink remains, then drain excess fat into a safe container.

Transfer the cooked beef to the crockpot. Add the diced potatoes, chopped onion, beef broth, garlic powder, and onion powder. Stir to combine.

Cover and cook on low for 6 to 8 hours or on high for 3 to 4 hours. The potatoes should be fork-tender when done.

Turn off the crockpot or set it to warm. Stir in the milk, shredded cheddar cheese, and sour cream until the cheese is melted and the soup is creamy.

Taste and season with salt and pepper. Serve immediately while hot.