Problems with Dither not functioning

When I set the output to less than the texture output and exported it, I could not confirm Dithering on the display.

Also, when I exported both with and without Dithering and compared the difference in pixels, there was no difference.

Is there some other setting I need to enable Dithering?

Texture Export Settings

File type"tiff, 8bits + dithering"

OutputMaps"BaseColor"