It seems like a bug but it could also be intentional I suppose. I don’t know what a public link is good for though if it isn’t making photos available to the public via a viewer or download without credentials. Internal users would be shared to and use the collaborative albums menu item. This is Nextcloud 25.0.2and Hub 3.
You can also share the file folder. That may be not so nice but perhaps bypasses the problem.
It is still strange that no one has found this really serious error before the introduction of the app. As if you do not share photo albums also publicly. Or is it only a problem with Nextcloud 25.0.2?