User-instanced subobjects owned by a streaming sublevel's Blueprint CDO cannot be garbage collected with the owning world after the sublevel has been reloaded in the editor.

UE - Gameplay - Blueprint - Feb 5, 2020

Strong object reference properties of an 'EditInline'-decorated UCLASS type embedded within a native C++ struct definition can be instanced at edit time by the user as part of a variable's default v ...

Arrays of user-defined structs are not initialized properly in a nativized Blueprint class.

UE - Gameplay - Blueprint - Feb 28, 2018

New elements are not being initialized properly when setting up the default value for arrays of user-defined structures in nativized Blueprint C++ constructor code. ...