ItemSelectedEventArgsConverter not found in schema

Question

I am using ItemSelectedEventArgsConverter on one page in my application. Everything works ok when using the iPhone emulator but when I push the build to test on a physical iPhone when i hit the page in question I get an error "Type xct: ItemSelectedEventArgsConverter not found in xmlns http://xamarin.com/schema"

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
             xmlns:local="clr-namespace:CertsAssured.Resources;assembly=CertsAssured"
             xmlns:xct="http://xamarin.com/schemas/2020/toolkit"
             x:Class="CertsAssured.View.AssetSearchResultPage"
             Visual="Material"
             x:Name="AssetSearchResults">
    <ContentPage.Padding>
        <OnPlatform x:TypeArguments="Thickness"
                iOS="0, 20, 0, 0" />
    </ContentPage.Padding>
    <ContentPage.Resources>
        <ResourceDictionary>
            <local:StringToColourConverter x:Key="StringToColourConverter">
            </local:StringToColourConverter>
            <xct:ItemSelectedEventArgsConverter x:Key="ItemSelectedEventArgsConverter" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <ContentPage.Content>
        <StackLayout Orientation="Vertical" Padding="10">
            <ListView ItemsSource="{ Binding Assets }"
                      HasUnevenRows="True">
                <ListView.Behaviors>
                    <xct:EventToCommandBehavior
                        EventName="ItemSelected"
                        Command="{ Binding AssetSelectedCommand }"
                        EventArgsConverter="{StaticResource ItemSelectedEventArgsConverter}" />
                </ListView.Behaviors>
                <ListView.ItemTemplate>
                    <DataTemplate>
......

Any ideas what could be causing this, I have "Link Framework SDKs Only" as Linker behaviour.

Thanks