How can I fix my Switch's resolution in docked mode?

Solution 1:

Have you tried manually changing the screen size via TV Settings?

  1. From the HOME Menu, select "System Settings."
  2. Scroll down the menu on the left-hand side of the screen and select "TV Settings."
  3. Select Adjust Screen Size. (Dock the console and follow the on-screen prompts to manually adjust the screen size)

Additionally, changing the TV Resolution here may also help.