Fullscreen game not rendering to proper size for resolutions besides 1920 X 1080

Question

I am working on a monogame project. When I started trying to test it on alternative resolutions, I encountered an odd issue. The game does not render properly to fullscreen on resolutions besides 1920 X 1080.

Here is the code I am testing with:

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace MonogameResTest
{
    public class Game1 : Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        Texture2D background;

        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }

        protected override void Initialize()
        {
            base.Initialize();

            graphics.PreferredBackBufferWidth = graphics.GraphicsDevice.DisplayMode.Width;
            graphics.PreferredBackBufferHeight = graphics.GraphicsDevice.DisplayMode.Height;

            graphics.IsFullScreen = true;

            graphics.ApplyChanges();
        }

        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);

            background = Content.Load<Texture2D>("OnTheWater12");
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.Black);

            spriteBatch.Begin();

            spriteBatch.Draw(
                background,
                graphics.GraphicsDevice.Viewport.Bounds,
                Color.White);

            spriteBatch.End();

            base.Draw(gameTime);
        }
    }
}

When I set my computer's resolution to 1920 X 1080, this works fine. It renders the image covering the entire screen, as expected. However, when I change the resolution to other values (I have tried 1280 X 720, 800 X 600, and 1600 X 900, for testing's sake) it renders to a rectangle in the center of the screen, rather than rendering over the entire screen. I have checked the values of Viewport.Bounds at runtime, and it is showing the same values as the resolution I set. What is going on here?