FBX textures do not get extracted when clicking the 'Extract Textures' button in the Inspector

To reproduce:
1. Open the project “TestFBXImportBug”
2. Select the Sign in the Assets → Models
3. Select the Materials tab in the Inspector
4. Click the “Extract Textures” button in the Inspector
5. Choose the “Textures” folder

Expected result: The .fbx file (DirectionSign) gets extracted to the “Textures” folder
Actual result: The “Textures” folder is empty

Reproducible with: 2019.4.31f1, 2020.3.39f1, 2021.3.9f1, 2022.1.16f1, 2022.2.0b7, 2023.1.0a10

Reproduced on: macOS Monterey 12.5.1 (Intel)

Notes:

• 2022.2.0b7, 2023.1.0a10 thorws Error “NullReferenceException: SerializedObject of SerializedProperty has been Disposed” after the steps above
• “Extract Materials” button works fine