Metal SM5 shader code cannot be viewed in the Editor on Mac

The Metal SM5 shader code cannot be viewed in the Editor for a Material. Prior to 4.20, only HLSL Code could be viewed. In 4.20, a number of additional shader options were added, and they all work with the exception of Metal SM5.

This only occurs on Mac. Metal SM5 shader code for iOS can be seen on Windows.

1. Create a new project.
2. Create a new Material.
3. Open the Material Editor.
4. Go to Window -> Shader Code -> Metal SM5 and select any of the quality options.

RESULT:
After compiling for a few seconds, no shader code is displayed in the window.

EXPECTED:
After compiling for a few seconds, the window displays the Metal SM5 shader code.