try disabling fit_canvas_to_parent

src/main.rs

@@ -90,7 +90,7 @@ fn main() {
                     resolution: (SCREEN.x, SCREEN.y).into(),
                     present_mode: PresentMode::AutoNoVsync,
                     // Tells wasm to resize the window according to the available canvas
-                    fit_canvas_to_parent: true,
+                    // fit_canvas_to_parent: true,
                     // Tells wasm not to override default event handling, like F5, Ctrl+R etc.
                     prevent_default_event_handling: false,
                     ..default()