How to reproduce:
1. Open the attached BugSR.zip project
2. Create a new GameObject in the Hierarchy
3. Add "MyBehaviour" Component in the Inspector window and click on the button "Print Animal Sounds"

Expected: Inspect the Console window the Cat sound is NOT null

4. Save the Scene, close and reopen the project
5. Select your created GameObject and press "Print Animal Sounds" button

Actual: Inspect the Console window, the Cat sound is null

Reproducible with: 2019.3, 2020.2

Note:
- Could not test with 2018.4 because of the thrown errors