ShowCreation doesn't draw properly

### The error
Hi, i just installed Manim and tested examples given on the website. And the line `self.play(ShowCreation(square))` doesn't work as expected. the lines of the square are not drawn correctly.

**Code**:
```
from manimlib import *

class InteractiveDevlopment(Scene):
def construct(self):
circle = Circle()
circle.set_fill(BLUE, opacity=0.5)
circle.set_stroke(BLUE_E, width=4)
square = Square()

self.play(ShowCreation(square))
self.wait()
```

### Visually

https://user-images.githubusercontent.com/10650661/111342428-bf62fe00-867a-11eb-830c-eb53b6264b6f.mp4

### Environment
**OS System**:
Mac os Big Sur 11.2.1
**manim version**:
Installed directly with pip
**python version**:
Tested in 3.9.0 and 3.8.2