On Thu, 2021-05-20 at 12:59 +0000, Anca, Tibor wrote:
Am Donnerstag, dem 20.05.2021 um 19:33 +0800 schrieb Ed Greshko:
Does

host host.name.de 192.168.3.33

Return the IP address you expect?
Yes. But it also returns:

Host xyz not found: 3(NXDOMAIN)

Are you trying to use just the hostname without the fully qualified domain name?

systemd resolved won't modify the nameservers listed in /etc/resolv.conf.  It uses different name servers based on the interface.  It won't query your VPN name servers if you only specify a hostname.  It will only use your VPN name servers if you specify a domain name that matches the domain names of your VPN.

This article gives a good overview of how it works, including on vpns.

https://fedoramagazine.org/systemd-resolved-introduction-to-split-dns/