Interface property is not shown in the Inspector when the null value is chosen while using the CustomPropertyDrawer attribute with the generic Object class

Note: See pinned comment for a possible solution.

 

How to reproduce:
1. Open the “ReportPropertyDrawer“ project
2. Open the “SampleScene“
3. Open the “Assets > ScriptableObjects > SerializeReferenceOnly.asset“ in the Inspector
4. Toggle on and off the “Ensure Animal is Not Null“ property
5. Select the “null“ value in the “Animal“ drop-down list
6. Observe the “Animal“ property

Expected result: The “Animal“ property gets set to the “null“ value
Actual result: The “Animal“ properties drop-down disappears

Reproducible with: 2022.3.37f1, 6000.0.10f1
Could not test with: 2021.3.40f1 (List is replaced with “No GUI Implemented” message)

Reproducible on: macOS 14.5 (Intel), Windows 11 (User’s)
Not reproducible on: No other environments tested

Notes:

• The issue only appears while working with the “null“ value with the Interface type field with generic base class and “SerializeReference“ instead of a custom “PropertyAttribute”
• Works correctly with the abstract classes