Hi Kim, long time no speak. Hope life is treating you and yours well.
I was just working on a demo and while doing so, setup to show external links. Seems to be working ok for me.
Tried to upload a small gif but this board is crazy and does not allow a small gif around 700k… Pretty silly if you ask me. Anyway: https://imgur.com/a/kdtH6uK
First button is internal url and bottom links is external, same in settings as yours.
Cheers!