Serializable integer variable changes are reset when entering the Play Mode

Reproduction steps:
1. Open the attached “ReproProject” project
2. Open the "Assets/Scenes/WorldScene.unity" scene
3. Select the “WorldManager” GameObject in the Hierarchy window
4. In the Inspector window change the Container Size value to a 16 in the World Manager (Script) component
5. Enter and then Exit the Play Mode
6. In the Inspector window change the Container Size value to a 5 in the World Manager (Script) component
7. Enter the Play Mode
8. Observe the Container Size value

Expected results: Container Size value stays at 5 when entering the Play Mode and saves the altered value
Actual results: Container Size value resets to 16 when entering the Play Mode

Reproducible with: 2023.2.0a18, 2023.2.0b17, 2023.3.0a13
Not reproducible with: 2021.3.32f1, 2022.3.13f1, 2023.1.19f1, 2023.2.0a17

Reproducible on: Windows 11
Not reproducible on: No other environment tested