How to reproduce:
1. Create a new 2D project
2. Create a new Square Sprite in the Project window (Right-click -> Create -> Sprites -> Square)
3. Create a new Material in the Project window (Right-click -> Create -> Material)
4. Drag the created Square Sprite into the Hierarchy window
5. Drag the Material onto the Square Sprite in the Hierarchy window
6. Observe the Scene view

Expected result: The Square Sprite is visible in the Scene view
Actual result: The Square Sprite is not visible in the Scene view

Reproducible with: 2018.4.29f1, 2019.4.14f1, 2020.1.13f1
Could not test with: 2020.2.0b11 and 2021.1.0a5 (Missing the options to create Sprites in the Create menu)

Notes:
- The workaround for this issue would be to rotate the Square Sprite by 180 degrees on Y-axis
- The issue is not reproducible with any other Sprites
- Switching the Camera mode to 3D can be seen that the Square Sprite is facing the opposite direction