Hi.
If you are fading a group of images , use "canvas group" component (set on a parent that has the things in it that you wish to fade. it should also work with Tween Fade.
if not, use Tween Float and Ui Canvas Group Set Alpha
Make sure time and other settings are correct
Also make sure when you start the game, the default setting (alpha 0/1) are correct.
I also noticed that fade is set to 255, i believe that the Tween Fade uses Alpha, which has only a range from 0 to 1