Reproduction steps:
1. Open the user’s attached project
2. Open the “Assets/Base.prefab”
3. In the Inspector Window, observe the empty list “The List”
4. Open the “Assets/Variant.prefab”
5. In the Inspector Window, click “Open”
6. Observe “The List”

Expected result: “The List” list is empty in “Assets/Base.prefab”
Actual result: “The List” contains the number of the “Assets/Variant.prefab” elements with the value of “0”

Reproducible with: 2020.3.39f1, 2021.3.9f1, 2022.1.16f1, 2022.2.0b7, 2023.1.0a9

Reproducible on: Windows 10 Pro 21H2