How to play a GIF infinitely in XAML?

My problem is that in my code the GIF plays once and then gets stuck. I've already tried various ways to solve this but unfortunately nothing helped. I tried stopping it, then setting it to position zero and playing it again. Declaring the GIF as source again didn't help. The only thing that worked was setting the source to $null and then setting the source again. However, this creates a very ugly flickering effect. Here is my current code:

function Get-Controls
{
    # Find and assign various UI controls from the loaded XAML window by their names

    $global:Load_Installing_lbl = $global:window.FindName("Installing_lbl")
    $global:Load_Loader_gpl = $global:window.FindName("Loader_gpl")

    $global:LoaderNum = 1
    $Load_Loader_gpl.Source = [Uri]::new("$PSScriptRoot\Loaders\Loader ($global:LoaderNum).gif")

    $global:Load_Loader_gpl.Add_MouseLeftButtonDown({
        $global:LoaderNum++
        if (-not (Test-Path "$PSScriptRoot\Loaders\Loader ($global:LoaderNum).gif"))
        {
            $global:LoaderNum = 1
        }

        # Reset the loader to ensure the new GIF will play infinitely
        $Load_Loader_gpl.Stop()
        $Load_Loader_gpl.Source = [Uri]::new("$PSScriptRoot\Loaders\Loader ($global:LoaderNum).gif")
        $Load_Loader_gpl.Play()
    })

    $Load_Loader_gpl.add_MediaEnded({
        $wert = [Environment]::GetEnvironmentVariable("Installation", "User")
        if ($wert -eq "FINISH")
        {
            [Environment]::SetEnvironmentVariable("Installation", $null, "User")
            $global:Window.Close()
        }
        else
        {
            # Temporarily set the source to null to reset the GIF
            $Load_Loader_gpl.Stop()
            $Load_Loader_gpl.Position = [TimeSpan]::Zero # Set the initial position to zero
            Write-Host "t0.20"
            $Load_Loader_gpl.Play()
        }
    })

    # Ensure the GIF plays in an endless loop initially
    $Load_Loader_gpl.Position = [TimeSpan]::Zero # Set the initial position to zero
    $Load_Loader_gpl.Play()
}

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="MainWindow" Height="300" Width="300" WindowStyle="None" AllowsTransparency="True" Background="Transparent">
    <Border CornerRadius="0, 20, 0, 20" Background="LightGray" BorderBrush="#FFFDC400" BorderThickness="5">
        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="*"/>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>
            <Label Name="Installing_lbl" HorizontalAlignment="Center" VerticalAlignment="Center" FontWeight="Bold" FontSize="24">Installing Test....</Label>
            <MediaElement Width="200" Height="200" Grid.Row="1" Margin="10" Name="Loader_gpl" LoadedBehavior="Manual" UnloadedBehavior="Stop">
            </MediaElement>
        </Grid>
    </Border>
</Window>

As described above, I'm trying to play a GIF infinitely using XAML and Powershell.

Solution

PlayLORD-SysOp deserves credit for his comment on this related answer; as of .NET 8:

Resetting the .Position property to [TimeSpan]::Zero before calling .Play() again does NOT work, but [TimeSpan]::FromMilliseconds(1) - specifically - does.
The information in How to: Repeat Media Playback does NOT apply - presumably it only applies to invariably "moving" media such as sound and video files.

$Load_Loader_gpl.add_MediaEnded({
  # ... (conditional code omitted)
  # Restart the animated GIF.
  $this.Position = [TimeSpan]::FromMilliseconds(1)
  $this.Play()
})