Also, how are you starting it? I’m looking at the Arch package in the AUR (not your distro, but just looking), and I notice that it includes a .service file. This means that it would be started as a service, and not as a user, like you’re probably attempting to do.
It looks like sonarr is not in the official Ubuntu mirrors. The website mentions adding a new repo to apt. Is this what you did, or something else?
https://sonarr.tv/#downloads-v3-linux