It can have many reasons as to why the server won’t connect again. Most likely one of the configurations changes caused it to loose internet connectivity. Don’t worry, it happens to everyone at some point.

I can’t tell you what exactly you did wrong, but I can give you tips on how to prevent it in the future:

Firstly, take the time to research about whichever service you want to change. Typically, there is a way to reboot any service, without rebooting the entire server. Once you figured that out, you can write a little script that backd up your original config, applies the new one and then reverts the old one back unless you manually cancel within 30 or more seconds.

This ensures that, if your server does loose internet connectivity, your changes are reverted automatically. If everything works as exoected, you just CTRL + C to cancel the rest of the script. Also make sure to spawn the script in an independant tool like tmux, so it doesn’t end with your session.

Only once you are sure that all your configs 100% work, you may or may not fully restart the server.