How to reproduce:
1. Open the user’s attached “unity object pool error.zip” project
2. Enter Play Mode
3. In the Hierarchy, select “ObjectPoolTester” GameObject
4. In the Inspector window, press the “Pull from pool” button 11 times
5. Press the “Return from pool” button 11 times
6. Observe the “Active objects” number under the “According to ObjectPool” text

Expected result: Number is 0
Actual result: Number is 1

Reproducible with: 2021.3.30f1, 2022.3.10f1, 2023.1.14f1, 2023.2.0b10, 2023.3.0a5

Reproduced on: macOS 13.4.1 (Intel)
Not reproducible on: No other environment tested

Note: “Target.ManualCountActive” returns correct number