xamarin forms app freezes while binding to nullable datetime - xaml

Question

While trying to show data over form in Xamarin Forms app, a property in the model which is nullable DateTime is freezing the app. I know this is the offending property because if I remove Xaml for this binding, everything works fine.
While stepping through the code, the LoginTime property from source (fetched from db) and the getter from ViewModel's User property are going into infinite loop. I can't possibly imagine why.
Model:
public class User : PersistentEntity
{
private string _userId;
public string UserId
{
get => _userId;
set => SetProperty(ref _userId, value);
}
private string _userName;
public string UserName
{
get => _userName;
set => SetProperty(ref _userName, value);
}
private string _email;
public string Email
{
get => _email;
set => SetProperty(ref _email, value);
}
private DateTime? _loginTime;
public DateTime? LoginTime
{
get => _loginTime;
set => SetProperty(ref _loginTime, value);
}
}
ViewModel:
public class SettingsViewModel : ViewModelBase
{
private readonly SettingsSession _settingsSession;
private User _user;
public User User
{
get => _user;
set => SetProperty(ref _user, value);
}
public SettingsViewModel(INavigationService navigationService, SettingsSession settingsSession)
: base(navigationService)
{
Title = "Settings";
_settingsSession = settingsSession;
}
private DelegateCommand _fetchUserCommand;
public DelegateCommand FetchUserCommand =>
_fetchUserCommand ?? (_fetchUserCommand = new DelegateCommand(ExecuteFetchUserCommand, CanExecuteFetchUserCommand));
async void ExecuteFetchUserCommand()
{
User = await _settingsSession.FetchUser();
}
bool CanExecuteFetchUserCommand()
{
return true;
}
}
View:
<TableView Intent="Settings">
<TableRoot>
<TableSection Title="User">
<ViewCell>
<StackLayout Orientation="Horizontal"
Padding="2">
<Label Text="User Id"
WidthRequest="150"
Margin="5,0,0,0"
VerticalOptions="CenterAndExpand"/>
<Entry WidthRequest="250"
HorizontalTextAlignment="Start"
VerticalTextAlignment="Center"
Placeholder="UserId"
Text="{Binding User.UserId}"/>
</StackLayout>
</ViewCell>
<ViewCell>
<StackLayout Orientation="Horizontal"
Padding="2">
<Label Text="User Name"
WidthRequest="150"
Margin="5,0,0,0"
VerticalOptions="CenterAndExpand"/>
<Entry WidthRequest="250"
HorizontalTextAlignment="Start"
VerticalTextAlignment="Center"
Placeholder="User Name"
Text="{Binding User.UserName}"/>
</StackLayout>
</ViewCell>
<ViewCell>
<StackLayout Orientation="Horizontal"
Padding="2">
<Label Text="Login Time"
WidthRequest="150"
Margin="5,0,0,0"
VerticalOptions="CenterAndExpand"/>
<Entry WidthRequest="250"
HorizontalTextAlignment="Start"
VerticalTextAlignment="Center"
Placeholder="Login Time"
Text="{Binding User.LoginTime, StringFormat='{0:dd-MM-yyyy HH:mm}'}"/>
</StackLayout>
</ViewCell>
</TableSection>
</TableRoot>
</TableView>
Any help is appreciated.