Tracks have an "Add" prefix in the Track Group right-click menu when their name contains a '/'

How to reproduce:

1. Open the attached project “IN-145379”
2. Open the “Assets/Scenes/Timeline” Timeline
3. In the Timeline window, right-click “Track Group”
4. Observe the menu list

Actual result: The "Example/Custom2/Custom2 Track” option appears as “Add Example” in the dropdown
Expected result: The "Example/Custom2/Custom2 Track” option appears as “Example” in the dropdown

Reproducible with: 1.8.6 (6000.0.0f1), 1.8.12 (6000.5.0f1), 6.6.0 (6000.6.0a7)

Reproducible on: macOS 26.5 (M4 Max), Windows 11
Not reproducible on: No other environments tested

Notes:

• Issue is not present in the “Add new tracks” button dropdown
• The “Custom2Track” script contains the following DisplayName: “[DisplayName("Example/Custom2/Custom2 Track")]”