Why is the property or indexer 'bool?.Value' cannot be assigned to --it is read only?

Hi, I'm trying to implement a radzen switch in my radzengrid:

<RadzenGridColumn TItem="UsersDTO" Property="IsSubscribed" Title="Is Subscribed?">
                        <Template Context="user">
                            <RadzenSwitch @bind-Value="user.IsSubscribed.Value" />

The property of the UsersDTO.IsSubscribed ->

public bool? IsSubscribed { get; set; }

I need my IsSubscribed property to be nullable as it is required somewhere else, but I keep getting the error
"Property or indexer 'bool?.Value' cannot be assigned to -- it is read only" error message, I've tried to find TValue in radzenswitch but that doesn't exist on there and I dont know how to or where is the error.

Can anyone tell me why it's not liking this code? thanks!