After further analysis, we found that having a public field that is named after the underlying property, causes a collision between the two public members. When the field gets initialized in the property setter, it turns out to have a null value, if the collision is resolved in its favor. In order to overcome this behavior, should either set the field's data access modifier to private, or change its name, in case you need it to be public.

As a workaround, you can try redefining the CellTemplate of the column placing a TextBlock to display the required values.