How to reproduce:
1. Open the user's attached project
2. Open scene Scenes/SampleScene
3. Go to Window -> Asset Management -> Localization Scene Controls
4. Set Active Locale to English
5. In the Hierarchy window, select "MainCamera"
6. In the Inspector window, select the context menu (three dots icon) next to the "New Behaviour Script" component
7. Select "Use" and observe the Console

Expected result: TestString is logged to the Console
Actual result: Null is logged to the Console

Reproducible with: 1.0.5, 1.2.1 (2019.4.37f1, 2020.3.32f1, 2021.2.17f1, 2022.1.0b14, 2022.2.0a8)

Notes: the string is returned correctly when in Play mode