I was trying to get raylib to render at native resolution on a Retina display, and added a call to ToggleFullscreen. When I ran the code, the window was fullscreen (though still at the effective resolution), but the rest of the graphics (my desktop and all of my other applications) were rendered at double their normal resolution, so they looked blurry and I could only see the top-left quarter of the screen.

When I killed the program, the graphics returned to normal. This is the code I used:

#include "raylib.h"

int main(void) {

    SetConfigFlags(FLAG_WINDOW_RESIZABLE | FLAG_VSYNC_HINT | FLAG_WINDOW_HIGHDPI);
    InitWindow(640, 400, "test");
    ToggleFullscreen();
    SetTargetFPS(60);

    while (!WindowShouldClose()) {
        BeginDrawing();
            ClearBackground(RAYWHITE);
            DrawText("TEST", 300, 200, 20, LIGHTGRAY);
        EndDrawing();
    }

    CloseWindow();
    return 0;
}

This was with raylib 5.5 on an M1 Mac (macOS 15.5). I would build raylib from source, but can't be bothered anymore. Sorry.