Steps to reproduce:
1. open user's attached project
2. open scene "Scene"
3. open Assets/Scripts/MyClass.cs in Visual Studio
4. place breakpoint at line 18, where the Debug.Log is located
5. attach Visual Studio Debugger to Unity
6. switch to Unity and press Play
7. when the breakpoint is hit, execute in Visual Studio Debug/Windows/Watch/Watch 1
8. insert (int)Fruit to the Watch window

Expected behavior: (int)Fruit value is 1 (VSTU should be able to display an enum to int expression properly)
Actual result: (int)Fruit returns an error "Node not supported '(int)Fruit'"

Reproduced with: 5.5.0a6, 5.4.0p3, 5.3.6p2
Not reproduced with: 5.2.5f1 (for some reason breakpoint is not reached in this version)

Note:
-when run in Visual Studio as .NET Console Application (see user's attached file "ConsoleApplication1.zip") no error is shown
-please have a look at user's attached videos