REGRESSION: Yes, this did not occur in 4.19
The user is able to drag an Event from My Blueprint panel into any graph, creating a duplicate Event Node.
Additionally the dupe Event will have extra output pins (this can be bugged separately if needed).
RESULT
Two Event Begin Play nodes now exist in the graph.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-64515 in the post.