When it scans for Parent it will also find the Child assets, becuase the class is "this or any subclasses". Primary assets cannot be registered to two types at the same time, so whichever type scans first generally wins. This is not a supported case, if you want to do this you need to put them in separate directories.
Any child class of UDataAsset (parent) will properly be picked up when the Asset Manager's Asset Base Class" field is set to the appropriate class. However a grandchild class (Child) with the same setup is not picked up.
This also occurs if Parent is a built in class. For example, PrimaryDataAsset shows up as expected by default, but a child of PrimaryDataAsset does not.
No - Same behavior occurs in 4.16.3 (CL 3561208)
Type summary shows Count as 2 for Parent (expected since Child is a subclass) But child Count shows as 0. (See screenshot)
Child count shows as 1 for the Child data asset.
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