Comment 10 for bug 1855758

That NAS seems pretty old, you might have to live with the configuration change to downgrade the protocol to SMB1. Maybe you can ssh into it and find out what samba version it's running, and tweak its config manually. I find it weird that samba, even from 2011, would reject SMB2 connections, or not work with them. Have you also looked for firmware upgrades?

About the dbus error, lxqt is in the universe repository and thus not strictly supported. If you could reproduce the error with a normal ubuntu desktop, that would be better. I tried a 20.04 desktop the other day, standard ubuntu-desktop, and could connect to my NAS just fine (a synology Ds216), but it doesn't show up in the "windows network" tab, just under "other locations".