Welcome in the community ,
I created a dummy doc with card view and you are right, the option to “Show all groups” or “Show only groups with values” seems not available anymore.
The only thing that comes in my mind is to create a new view and make it a simple table view, then to add “fake” values to the groups that don’t have content and after that to delete this content.
Hopeful, after that the groups without content will remain visible
It could have been that when the system was updated, your scenario wasn’t foreseen.
Just for curiousity, keep me updated