SceneCaptureComponent2D Component does not allow the use of the Hidden Actor array and the Show only actors array does not take in elements. This issue does not occur in 4.16.3 because the feature was not implemented in that version.
4.16.3 - CL: 3651208 - Feature is not present
4.17.1 - CL: 3586342 -Issue occurs
4.18 - CL: 3635932 - Issue occurs
Head over to the existing AnswerHub thread and let us know what's up.