Yes. It is indeed an issue of repository priorities. You should be able to get the latest version of Netdata by increasing the priority of the http://repository.netdata.cloud/repos/stable/ubuntu repository to at least 1001 (the current priority of the system repositories) by creating a file in /etc/apt/preferences.d with the exact contents:
Package: *
Pin: origin "repository.netdata.cloud"
Pin-Priority: 1001
Alternatively, you could take a similar approach to lower the priority for mirror.hetzner.com and archive.ubuntu.com to 500 or lower (500 is the default priority for system repositories on Ubuntu and Debian systems).
Either way, once you update the priority configuration, you should be able to just run apt upgrade netdata to get the correct version of Netdata.