How to reproduce:
1. Open the “ForwardPlusCustomShaderBug“ project
2. Open the “Demo“ scene
3. Enable the "Custom Shader" GameObject and disable the "Lit" GameObject in the Inspector window
4. Set the Rendering Path to Forward+
5. Resize the Scene view window
6. Observe the Spot Light behavior in the Scene view window

Expected result: The Spot Light illuminates the “Sphere“ and “Plane“ GameObjects regardless of the Scene view window size
Actual result: The Spot Light illuminates the “Sphere“ and “Plane“ GameObjects only when the Scene view window is shrinked

Reproducible with: 2022.3.12f1, 2023.1.19f1, 2023.2.0b16, 2023.3.0a12
Could not test with: 2021.3.32f1 (Forward+ is not an option for Rendering Path)

Reproducible on: macOS 13.5.2 (Intel)
Not reproducible on: No other environment tested

Notes:
- The same behavior happens when resizing the Game view window
- The Spot Light also starts illuminating the GameObjects when zoomed closer to them
- The Spot Light also starts illuminating the GameObjects when the Outer Spot Angle is more than 90 depending on the Scene view window size