I've tried multiple times to hide playlists by right clicking and choosing "make secret" however they still all show up publicly.
I have tried from Windows 10 and Android.
Just to confirm. When you mentioned that the Playlists are still showing up publicly, you mean that they appear on your Profile or just can be accessed using the playlist link?
Also, when you right-click on the "secret" playlist, does the option "Make Public" appear or you're still getting the "Make Secret" button?