Reproduction steps:
1. In the “{Project Root Folder}/ProjectSettings” folder open “ProjectSettings.asset” file with any text editor
2. Search for “scriptingBackend” field and note the values
3. Open the attached project “ILL2CPPSettingsNoSave”
4. Open the Project Settings window (Edit > Project Settings)
5. In the Project Settings window open the Player tab
6. Change the “Scripting Backend” field from “Mono” to “IL2CPP”
7. Repeat steps 1 and 2

Expected result: The “scriptingBackend” values are automatically saved into the save file
Actual result: The “scriptingBackend” values are only saved when saving the project manually

Reproducible with: 2020.3.47f1, 2021.3.24f1, 2022.2.17f1, 2023.1.0b15, 2023.2.0a13

Reproducible on: macOS 13.3 (Intel)

Note: This also affects settings like “IL2CPP Code Generation” and other settings related to IL2CPP