您可以在导航到另一个页面后将SelectedModel设置为null。
请参考以下代码片段：

private Key _selectedModel;
        public  Key SelectedModel
        {
            get { return _selectedModel; }
            set
            {
                SetProperty(ref _selectedModel, value);

                if (SelectedModel != null)
                {  
                    Shell.Current.GoToAsync(nameof(DetailPage));
                    
                    // set the SelectedItem to null here
                    SelectedModel = null;
                }

            }
        }

我在我这边实现了这个功能，大家可以参考我的viewmodel的完整代码：

public class MyViewModel: INotifyPropertyChanged 
    {
        public ObservableCollection<Rayon> Sections { get; set; } = new ObservableCollection<Rayon>();

        private Rayon _selectedModel;
        public Rayon SelectedModel
        {
            get { return _selectedModel; }
            set
            {
                SetProperty(ref _selectedModel, value);

                if (SelectedModel != null)
                {

                    Shell.Current.GoToAsync(nameof(DetailPage));

                    SelectedModel = null;
                }

            }
        }

        public MyViewModel() {
            Sections.Add(new Rayon { SectionName= "section_1",Price=100.0});
            Sections.Add(new Rayon { SectionName= "section_2", Price = 100.0 });
            Sections.Add(new Rayon { SectionName= "section_3", Price = 100.0 });
    
        }
    
        bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
        {
            if (Object.Equals(storage, value))
                return false;
            storage = value;
            OnPropertyChanged(propertyName);
            return true;
        }
        protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
        public event PropertyChangedEventHandler PropertyChanged;

    }

注：

记住将Mode设置为TwoWay。
用法示例：

<ListView ItemsSource="{Binding Sections}" HasUnevenRows="True" 
              SelectedItem="{Binding SelectedModel,Mode=TwoWay}"
              >

              <!--  other code -->
     </ListView>