Hello friends,
There is a problem that if you set the background color (rendering > environment > clear color) to something very light, you are unable to see the grid.
According to this pull request, a feature has been added to Godot to let you change the grid color, but I am unable to find anywhere to change it: https://github.com/godotengine/godot/pull/21154
Compare here the grid with the default clear color versus the grid with very light color set in the default clear color in the rendering > environment settings.