Hi,
Having a weird one whereby I get the red square when I try and connect to SMB via next cloud client using a directory. If I remove the directory option (and make it root), I get a green circle, but I have the problem where the external storage just redirects (https://github.com/nextcloud/server/issues/8364)
Using smbclient from the command line on the same machine works even more weirdly, so I don’t think it’s a firewall issue…