Select selectedItem not showing

Hello,

I've a problem with my Fiori-like test application. When I place a select on my master-page then I have the same functionality as on https://sapui5.hana.ondemand.com/sdk/test-resources/sap/m/demokit/explored/index.html#/sample/select

When you select an item in the select it is highlighted

But when I place the same select on my detailpage (actually EditPage) my selecteditem shows up, but when selecting a new one it is not highlighted...

Can this be a bindingContext problem?

I created a gist-repository with my code in it.

https://gist.github.com/panni/9161465

Thanks in advance.

Kind regards,

Robin