UserControl: This PlotModel is already in use by some other PlotView control

Question

I know this question has been posted already, but I don't understand the answers. In My case I have a project with only a UserControl:

<UserControl x:Class="SimpleOxyPlotUserControl.UserControl1View"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:SimpleOxyPlotUserControl"
             xmlns:oxy="http://oxyplot.org/wpf"
             mc:Ignorable="d" 
             x:Name="uc1"
             d:DesignHeight="450" d:DesignWidth="800">
    <Grid>
        <oxy:PlotView Model="{Binding ElementName=uc1, Path=OxyPlotModel, Mode=TwoWay}"/>
    </Grid>
</UserControl>

and its code behind:

using System.Windows;
using System.Windows.Controls;
using OxyPlot;

namespace SimpleOxyPlotUserControl
{
    /// <summary>
    /// Interaction logic for UserControl1View.xaml
    /// </summary>
    public partial class UserControl1View : UserControl
    {
        public UserControl1View() => InitializeComponent();

        public PlotModel OxyPlotModel
        {
            get { return (PlotModel)GetValue(OxyPlotModelProperty); }
            set { SetValue(OxyPlotModelProperty, value); }
        }

        public static readonly DependencyProperty OxyPlotModelProperty =
            DependencyProperty.Register("OxyPlotModel", typeof(PlotModel), typeof(UserControl1View),
                new PropertyMetadata(new PlotModel()));
    }
}

Then I have another project with a simple WPF App and its MainWindow.xaml:

<Window x:Class="SimpleOxyPlotUserControlApp.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:simpleOxyPlotUserControl="clr-namespace:SimpleOxyPlotUserControl;assembly=SimpleOxyPlotUserControl"
        Height="350" Width="525">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <simpleOxyPlotUserControl:UserControl1View/>
        <simpleOxyPlotUserControl:UserControl1View Grid.Row="1"/>
    </Grid>
</Window>

and its code behind:

using System.Windows;

namespace SimpleOxyPlotUserControlApp.Views
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }
}

I receive the error message "InvalidOperationException: This PlotModel is already in use by some other PlotView control."

I know this is, because each Oxy PlotModel can only be connected to exactly one Oxy PlotView. But why does it not create a new Oxy PlotView and PlotModel each time, when I insert my UserControl? And how can I ensure that it does so?