Try running on winforms

AM2RPortHelperGUI/AM2RPortHelperGUI.Wpf/AM2RPortHelperGUI.Wpf.csproj

@@ -10,6 +10,7 @@
     </ItemGroup>
 
     <ItemGroup>
+        <PackageReference Include="Eto.Platform.Windows" Version="2.7.0" />
         <PackageReference Include="Eto.Platform.Wpf" Version="2.7.0" />
     </ItemGroup>
 

AM2RPortHelperGUI/AM2RPortHelperGUI.Wpf/Program.cs

@@ -8,6 +8,6 @@ static class Program
     [STAThread]
     public static void Main(string[] args)
     {
-        new Application(Eto.Platforms.Wpf).Run(new MainForm());
+        new Application(Eto.Platforms.WinForms).Run(new MainForm());
     }
 }