WPF ToolTip does not update

Question

Assuming I have a simple class that represents a staff member

class Staff
{
    public string FirstName { get; set; }
    public string FamilyName { get; set         


        

Answer 1

I was having the same problem of it not updating. I found the solution to be adding the controls to a ToolTip template:

I don't quite understand why this is needed or why this makes it behave differently but it fixed the problem.