Linear Gradient not consistent

Trying to get a linear gradient working in a filled object (bez shape). It seems to work fine if object is vertical or horizontal but if skewed, I don’t get much fading.
(Objects left to right)
1 - object with no gradient
2 - Tall object with gradient angle at 90
3 - Tall object with gradient angle at 0
4 - Tilted object with gradient angle of 30
There barely any change in the base color of the tilted object when it should go from dark grey to light grey
Screen Shot 2020-05-17 at 2.09.08 PM

i don;t have much knowledge on this concept i think u did good great
辦公室還原