Hi Brian,
Thanks for contacting Syncfusion Support.
MVVM cross bindings are not effected for the controls that are created in native platform and shipped to Xamarin through binding assemblies. So, we currently do not have support for MVVM cross binding support for our controls.
We have also raised a ticket regarding this in Xamarin support forums and you can refer the following link regarding the same.
https://forums.xamarin.com/discussion/61149/mvvm-cross-binding-for-native-library-custom-controls Regards,
Hemalatha M.R