Reproduction steps:
1. Open the attached project “EnumProject”
2. Open the “Assets/EditorTest.cs” script and observe both variables (v1,v2)
3. In Unity’s Main Menu open “SSCCE>Show Test Window”
4. Observe that the first(v1) enum field has no default value displayed in the “DefaultNamespace.EditorTest” Window

Expected result: Value “A” is displayed in the first(v1) enum field
Actual result: No default value is displayed in the first(v1) enum field

Reproducible with: 2020.3.44f1, 2021.3.18f1, 2022.2.5f1, 2023.1.0b1, 2023.2.0a4

Reproducible on: Intel macOS 13.2

Note: The variable “v1” utilizes the static type “Enum” as a cast. The issue seems to be with using the Enum type as a generic type. When the EnumField's Init method is called with the Enum type, it is not able to determine the specific enum type at runtime, so it is unable to correctly display the value in the editor. By using a specific enum type instead of the Enum type as the generic type, the EnumField is able to correctly display the value.