Intellisense does not seem to work properly in VS for Mac 2019

I've recently upgraded to VS for Mac 2019. Have just created a vanilla project using Xamarin.Forms 3.6.0.264807 and Xamarin.Essentials 1.0.1.

Intellisense does not appear to work properly when I'm editing a XAML file. See image below.

There should be more options that appear in the list. Also, there is no error highlighting (if I try and set a property on Button called Foo for instance).