Getting ArgumentOutOfRangeException on line with no collection, argument or index!

[SoftCircuits]

I have a Razor Pages web application (.NET 8.0) with the following code in my markup.

@for (int i = 0; i < rows; i++)
{
    if (i < Model.DepartTruck.ProductSources.Count)
        isStorage = Model.DepartTruck.ProductSources[i].IsStorage;
    else
        isStorage = Model.IsStorage;

    // Markup

}

It's possible for Model.DepartTruck.ProductSources to be empty. That is the reason for this if statement. However, when I run it, an ArgumentOutOfRangeException is thrown.

In this case, Model.DepartTruck.ProductSources is empty and i is zero. So why the exception? And look at the line where the exception occurs! The highlighted line has no collection, no argument and no index.

Model is my page model. And IsStorage is a public bool variable in the model.

Does anyone know why I am seeing this?

[CyrusNajmabadi]

Not a question about the design of the c# language. You could try stack overflow. Or one of the discord channels linked to from dotnet/Roslyn.