The NAS is running a docker instance of pi-hole That software blocks ads, but it also allows one to set up local DNS. The router should now be exposing the NAS/pihole DNS and itself as a DNS server. You can check if it is working by name resolving mokupro1 or checking that your DNS is set to 192.168.50.94 (the NAS) and 192.168.50.1 (the router).

See how to log in to add DNS entries and the password at:

https://wiki.mccullerlab.com/Main/LabSecrets

The VPN isn't yet set up to forward the DNS entries, but I'll do that soon and post a comment.