When the order of construction is backwards it makes it impossible to have native objects set up components in OnConstruction, that a child BP Construction Script then has access to. Sometimes the C++ Construction is called before the Blueprints but if you toggle a setting on the BP, such as 'Use Controller Rotation Pitch', the Blueprint is called first.
Attached is a repro project with the steps already setup.
This was reported and tested in 4.22.3 (7053642). This was reproduced in 4.21.2 (CL-4753647), 4.23 (CL-7173969), and Main 4.24 (CL-7174533)
Results:Child Blueprint Construction Script logging occurs before Parent OnConstruction logging
Expected: Parent OnConstruction logging, followed by child Blueprint Construction Script logging
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-76782 in the post.