Single bit enum options become invisible in the Inspector when combined enum options are declared above them

Reproduction steps:
1. Open the attached “IN-125050” project
2. Open the “SampleScene”
3. In the Hierarchy, select the “GameObject”
4. In the Inspector, navigate to the “AllowedSidesToAttach” enum in the “TestScript” component
5. Observe the available options for the enum

Expected result: All options are visible
Actual result: The single bit options after “combined” options are not visible

Reproducible with: 2022.3.69f1, 6000.0.62f1, 6000.2.13f1, 6000.3.0f1, 6000.4.0a4, 6000.5.0a1

Reproducible on: Windows 11 (by reporter), macOS 26.1
Not reproducible on: No other environments tested

Workaround: Leave the combined options at the end of the enum