Reproduction steps:
1. Open the attached “IN-103909” project
2. Open the Project Settings window (Edit > Project Settings)
3. Make sure Domain Reload is disabled under the “Editor” tab
4. Open the “Scenes/SampleScene” Scene
5. Enter the Play Mode
6. Observe the Game View

Expected result: Pool has 100 inactive GameObjects
Actual result: Pool has 0 inactive GameObjects

Reproducible with: 2022.3.58f1, 2022.3.63f1, 6000.0.51f1, 6000.1.9f1, 6000.2.0b7
Not reproducible with: 2022.3.57f1

Reproducible on: Windows 10, Windows 11 (user)
Not reproducible on: No other environment tested

Notes:
- When Domain Reload is enabled, the bug no longer reproduces
- If in the “Start” function, the pool initialization is delayed by one frame, the pool initializes correctly