Permissions/Ownership ignored on home-folder on external drive

Hi,

I have installed latest version of Catalina on an external SSD. After installation I verified and everything works ok. I have separate user-accounts for admin and some standard-users. Now I moved some home-folders of standard-users to another partition (by copying homefolder and changing homefolder-settings in system-preferences/users and groups/advanced settings).

This seems to work ok, until I noticed that user A has read and write-acces to all stuff in user B's homefolder and visa versa?! Even after setting the permissions manually, the ownership seems to be for the user that is logged on. In terminal the currently-logged-on-user is shown as as owner of files from another users homefolder.

Is there a way to set permission on homefolders on a drive separate from OS-bootdrive, to make them as secure as if they were on the system-drive?