Reproduction steps:
1. Open the attached project “CoreRp“
2. Open the Scene “Assets/Scenes/SampleScene“
3. In the Hierarchy window select the GameObject “Test”
4. In the Inspector window add a List item to the “Keys” list
5. Observe the Console window

Expected results: It is possible to add a key or a value
Actual results: ArgumentOutOfRangeException error is thrown in the Console window

Reproducible with: 2020.3.45f1, 2021.3.20f1, 2022.2.10f1, 2023.1.0b7, 2023.2.0a5

Reproducible on: Windows 11