You say you’ve tried undoing the binding, but have you tried rebinding back to source control?
In Visual Studio:
- Open a solution with the problem
- Choose the solution in Solution Explorer
- Pick File->Source Control->Change Source Control
Visual Studio 2013/2015: File->Source Control->Advanced->Change Source Control - Unbind any projects that are bound but not working correctly.
- Bind all projects that are now unbound.