Numerous configurations require the exact hostname on a Debian system. If your hostname is something that you need to change, follow this article:
There are two places that you have to visit to change the hostname on a Debian system:
- /etc/hosts
- /etc/hostname
After you’ve made the changes, use the ‘hostname’ command to check if it worked.
Reference:
https://www.vultr.com/docs/how-to-change-your-hostname-on-debian