Server not reachable through LAN

Hi all,

I have just upgraded to a new router, which is using another local IP range. After editing the router setup and the apache2 config I managed to be able to reach the Nextcloud by the domain name as intended. I have no problems to access the server from a foreign network. However I cannot reach the server when I am in the same network and I type in its local IP address (which is 192.168.178.6). Instead it is redirecting me to an outdated DNS from another domain sellor that I used in the past for this server. I just cannot remember which config I forgot to edit, but I want to be able to reach the server locally too.

What I did is updating nextcloud.conf-file in the apache2 settings under /etc/apache2/sites-available/nextcloud.conf, which is mirrored to /etc/apache2/sites-enabled. I updated it to the new local IP address in my network.
Also I edited from old to new IP address in the config-file from Nextcloud itself under /etc/www/nextcloud/config/config.php.
But somehow I am still not able to reach the server locally. What place have I missed out editing?

I double-checked both files I mentioned above and they both use the new DNS domain name, not the outdated one… so I really wonder where this comes from. Any help appreciated!