How to reproduce:
1. Open the attached project (CustomInspectorTest.zip)
2. Open scene Scenes/SampleScene
3. In the Hierarchy, select the GameObject "MainCamera"
4. In the Inspector window, under the Property Drawer Example (Script) component, expand Collection -> Entries
5. Add an element to Entries by pressing the + sign
6. Collapse the Names and Counts foldouts by pressing the arrows next to them
7. Select the GameObject "Directional Light" in the Hierarchy, then "MainCamera" again
8. Observe the Names and Counts elements

Expected result: the lists remain collapsed
Actual result: the lists are expanded

Reproducible with: 2021.2.0a19, 2021.3.0f1, 2022.1.0b16, 2022.2.0a10
Not reproducible with: 2019.4.37f1, 2020.3.33f1, 2021.2.0a18

Notes: the lists also expand when adding or removing elements from the parent list