Preheat. Preheat the oven to 350°F. Lightly grease a 9x5-inch loaf pan or line a rimmed baking sheet with foil.
Soak the crackers. In a large bowl, combine the crushed saltines and milk. Let sit for 5 minutes until softened.
Mix the meatloaf. Add the ground beef, ground pork, eggs, onion, green pepper, garlic, ketchup, Worcestershire sauce, salt, pepper, and thyme. Mix gently with your hands just until combined. Do not overmix.
Shape. Press the mixture into the prepared loaf pan or shape into a 9x5-inch loaf on the baking sheet.
Make the glaze. In a small bowl, whisk together the ketchup, brown sugar, apple cider vinegar, Worcestershire sauce, and mustard until the sugar dissolves.
First glaze and bake. Spread half of the glaze over the top of the meatloaf. Bake for 45 minutes.
Second glaze. Carefully drain any excess fat from the pan. Spoon the remaining glaze over the top.
Finish baking. Return to the oven and bake for 15 to 25 minutes more, until the internal temperature reaches 160°F and the glaze is thick and caramelized.
Rest and serve. Let the meatloaf rest for 10 minutes before slicing. Serve warm.