Even after fixing the 3D rendering aspect ratio, certain elements of the User Interface (like the main menu background, mini-map circles, and loading screens) may still appear slightly wide or stretched. This occurs because these specific elements are static 2D image assets hardcoded into the game files.
If you are playing the base game and your desired resolution is missing from the menu, you can force it manually: Navigate to: heroes 5 widescreen fix 2021
1. The Ultimate Solution: HoMM 5 Content Combo Pack (Campaign Port) Even after fixing the 3D rendering aspect ratio,