We are not sure we understand what the issue exactly is.
We tested the mentioned ShellPrism example
from our SDK repository with our latest version of Telerik UI for WPF and the example loaded all of its views correctly. Note that the example uses Implicit Styles
and you should add references to the No.XAML version of the required Telerik assemblies in the project.
I recorded a short video for you showing how the example runs on our side, you can find it attached to my response. If we have missed something please let us know.