Problem accessing "Public" folders on a multi-user Mac

Hi. I want to use the Public folders on a multi-user Mac to share documents, but the other users can't access my Public folder (and vice versa). When we try, we get the message: "The folder “Public” can’t be opened because you don’t have permission to see its contents." If I try to put a document into another user's Public folder, nothing happens. Each user's folders in the Finder screen are all marked with a little "no access" icon, including the Public folder. If I try to access another user's Public folder by using "Go to Folder" in Finder, I can find the other user, but not their Public folder.

All the users have switched File Sharing on and have selected "Read & Write". We've also ticked the "Share files and folders using SMB" box.

The Mac is about 9 months old and running Ventura.

I feel there must be some other setting hiding somewhere that's blocking any sharing. Can anyone suggest a solution....? Thanks.