Microsoft.Maui.Controls.SolidColorBrush is already a child of Syncfusion.Maui.Scheduler.HeaderLayout iOS crashes in Release Mode

Question

I just wanted to update my .NET MAUI App in the Stores and tried to test it in Release Mode iOS. On Android everything worked as it should. But in the Release Mode on iOS first it didn't run, then it ran after a few tries but it crashed when navigating to a specific page with the following content:

<Grid>
    <syncfusion:SfScheduler
        x:Name="scheduler"
        AllowedViews="Day,Week,Month"
        FirstDayOfWeek="Monday"
        Tapped="SchedulerTapped">
        <syncfusion:SfScheduler.AppointmentMapping>
            <syncfusion:SchedulerAppointmentMapping
                Id="Id"
                Subject="Name"
                StartTime="From"
                EndTime="To"
                Background="Background"/>
        </syncfusion:SfScheduler.AppointmentMapping>
    </syncfusion:SfScheduler>

    <skia:SKLottieView
        x:Name="AnimationLoading"
        Source="animation_loading.json"
        RepeatCount="-1"
        HeightRequest="100"
        IsAnimationEnabled="True"
        IsVisible="False"
    />
</Grid>

that's the whole content of the page. The only thing I´ve changed since the update is that I added the LottieView.

The content of the Calendar are Appointments which are stored like this:

public class Appointment
{
    public string Id { get; set; }
    public string Name { get; set; }
    public bool Own { get; set; }
    public DateTime From { get; set; }
    public DateTime To { get; set; }
    
    public int BackgroundInt { get; set; }

    [NotMapped]
    public Brush Background
    {
        get
        {
             return new SolidColorBrush(Color.FromArgb($"000000{BackgroundInt:X}"[^6..]));
        }
    }
}

The reason for the [NotMapped] is that I store these items in a local db and this datatype is not accepted in sqlite.

As I said before, in the debug mode everything works perfectly but something I recognised is a warning while debugging which occurs exactly on the point when the app crashes in release mode. It's this warning:

Microsoft.Maui.Controls.Element: Warning: Microsoft.Maui.Controls.SolidColorBrush is already a child of Syncfusion.Maui.Scheduler.HeaderLayout. Remove Microsoft.Maui.Controls.SolidColorBrush from Syncfusion.Maui.Scheduler.HeaderLayout before adding to Syncfusion.Maui.Scheduler.HeaderLayout.

But after researching for a few hours I still have no clue. Can somebody help me???