Fitlering doesn't work when <Template> is used in DataGrid

I have this column in a grid where I show the license pate of a car. I have two fields in my data model where the license plate can be present. But its always in one or the other variable, depending on where the data comes from that I store in the model. Hence, I use the template to show the content of the second field if the first is empty. I noticed that I cannot filter in that column. Although I have a car with the licenseplate 1234AB, it won't show up when i search.

<RadzenGridColumn TItem="MyView" Property="RegistrationNumber" Title="License Plate" Width="80px" >
             <Template Context="context">
                    if (!string.IsNullOrEmpty(context.RegistrationNumber))

Filtering will work on Data by defined Property, not by what’s displayed in a template. You might need to extend your model with a new property that will return the value similar to the template logic and use this property for filtering.