Localization Xamarin.iOS in Storyboards

Hi mates,

I try to localize strings in storyboard in Xamarin.iOS using Visual Studio 2017 but nothing seems to works. I create a project structure like this :

I also specify the available language and the default in info.plist :

<key>CFBundleLocalizations</key>
<array>
    <string>en</string>
</array>
<key>CFBundleDevelopmentRegion</key>
<string>fr</string>
<key>UIMainStoryboardFile</key>
<string>MainStoryboard</string>

Something looks weird in my solution: The Localization IDs are always only numeric compare to what i can see in online docs where it's always like "zwR-D9-hM1"... normal ??

My MainStoryboard.strings items looks like ""30664.title" = "Localized Text";

Thanks for your helps,