When looking at the details of a UObject contained in a Data Asset, some categories are shown even though they should not be. If a category is marked as hidden in the parent class, it will be shown in the Data Asset (though variables in that category will not be shown). In addition, if a UFUNCTION from the Blueprint's parent class has been overridden in the Blueprint, another empty category named "Event Graph" will be shown in the Details panel.
REGRESSION:
Yes. In 4.20.3, hidden categories and the "Event Graph" category are not shown in the Details panel.
RESULT:
The "Do Not Show" category is shown (but the variable in the category is not), and there is another category present named Event Graph.
EXPECTED:
Only the Default category is shown since the other categories are empty (as far as the Details panel is concerned).
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-66428 in the post.