I don't understand why I can't do gradient fill on a square in manimgl-1.7.1 version

[gd247217]

Describe the error

I want to implement gradient filling inside the square in manimgl, but using set_color_by_gradient cannot achieve the effect I want.

Code

from manimlib import*
sin=np.sin
cos=np.cos
My_color=[BLUE_E,WHITE]
class MainScene(Scene):
    def construct(self) -> None:
        tex=Tex(r"a^2+b^2=c^2",font_size=200).to_edge(UP)
        sq=Square(fill_opacity=1)
        
        tex.set_color_by_gradient(*My_color)
        sq.set_color_by_gradient(*My_color)
        
        self.add(tex,sq)

Output

Wish get help

Environment

OS System: Window11
manim version: manimgl v1.7.2 But when I run the version number in the terminal, it shows 1.7.1
python version:python v3.12.8

[mathematics128]

It seems that manimgl colored the square's edge by the gradient you set, but not the whole square...