Files with umlauts are no longer displayed in Nextcloud 28

I don’t use Mac a lot but maybe it helps to check file permissions/attributes in the samba-dc container to find differences between shown and not shown files.

Enter samba-dc container:

runagent -m samba1 podman exec -ti samba-dc bash

In this example the files of share1 are listed:

ls -la /srv/shares/share1

Samba provides some enhancements for Mac, check out Configure Samba to Work Better with Mac OS X - SambaWiki

How to edit smb.conf in NS8: