problem with FSharp.Charting on Xamarin

I am running on Xamarin 6.3 on MacOS Sierra on a recent iMAC

I have loaded FSharp.Charting.Gtk (0.90.14)

1) Problem when executing after compilation

this is what I get

The beginning of the error log looks like

> Last login: Thu Apr 20 00:55:57 on ttys000
> 59x159x64x204:~ ...$ clear; cd "/Users/.../bin/Debug"; export PKG_CONFIG_PATH="/Applications/Xamarin Studio.app/Contents/Resources/lib/pkgconfig:/Library/Frameworks/Mono.framework/Versions/4.8.1/lib/pkgconfig"; export PKG_CONFIG_LIBDIR=""; export PATH="/Library/Frameworks/Mono.framework/Commands:/Applications/Xamarin Studio.app/Contents/Resources:/Applications/Xamarin Studio.app/Contents/MacOS:/usr/bin:/bin:/usr/sbin:/sbin"; export MONO_GAC_PREFIX="/Applications/Xamarin Studio.app/Contents/Resources"; export XBUILD_FRAMEWORK_FOLDERS_PATH=""; "/Library/Frameworks/Mono.framework/Versions/4.8.1/bin/mono32" --debug "/Users/.../bin/Debug/The42project.exe" ; echo $? > /var/folders/gm/z065gk616xg6g0xgn4c7_bvc0000gn/T/tmp1493d63.tmp; echo; read -p 'Press any key to continue...' -n1; exit
>
>
> (process:14805): GLib-GObject-WARNING **: invalid (NULL) pointer instance
>
> (process:14805): GLib-GObject-CRITICAL **: gulong g_signal_connect_data(gpointer, const gchar *, GCallback, gpointer, GClosureNotify, GConnectFlags): assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
>
> (process:14805): Gtk-WARNING **: Screen for GtkWindow not set; you must always set
> a screen for a GtkWindow before using the window
>
> (process:14805): Gdk-CRITICAL **: GdkColormap *gdk_screen_get_default_colormap(GdkScreen *): assertion `GDK_IS_SCREEN (screen)' failed

full error message here
https://gist.github.com/FaguiCurtain/a70fb8d894199f0a65de3a9006fb4758

2) problem when executing in FSI

in FSI, the chart window opens immediately but it takes 20-30 sec for the chart to actually appear.
is it normal it takes so long ?
When i hover on the chart, i see no coordinates, is it normal ?
i cannot close this window. As you can see on the screenshot, the 3 buttons on the upperleft of the chart window are not activated. I cannot find a way to make this window disappear. is it normal ?

thanks