When a widget Blueprint that is derived from a custom UserWidget class containing a custom EditInlineNew UObject class property is compiled, any value that has been set in the UObject property is reset to None.
This is almost certainly the same issue as UE-21890.
The "Display This Data" property is reset to "None."
The value set in the "Display This Data" property remains as it was set before the Blueprint was compiled.
If the "Display This Data" property is set in the Details panel of the Graph tab and the Blueprint is compiled, the value remains set and can then be used in either the Graph or Designer tabs.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-38276 in the post.