Alright we’re getting closer to find your issue.
INFO |ServerLibPriv | |TeamSpeak 3 Server 3.13.3 (2020-12-16 14:17:05)
First of all just as tip, update your server to the latest version (3.16.6) - download it here.
That’s not the cause of your problem but recommended anyways.
INFO |DatabaseQuery | |dbPlugin name: SQLite3 plugin, Version 3
Your server is using SQLite, no external database environment.
That means a restart of MySQL if that’s even installed on your system doesn’t affect TeamSpeak at all.
Restarting Apache2 doesn’t affect TeamSpeak, too as I mentioned above as well as it doesn’t affect MySQL if it would be installed your system.
WARNING |ServerLibPriv | |The system locale is set to “C” this can cause unexpected behavior. We advice you to repair your locale!
You should think about to change your system locate to get rid of this warning.
(it’s basically the language configuration of your local system)
Still this shouldn’t be the cause of receiving a shutdown signal but let’s fix this as well.
SystemInformation: Linux 4.15.0-144-generic #148-Ubuntu SMP
TeamSpeak requires to use
Display all available locales:
If both packages are missing, generate them:
locale-gen en_US.UTF-8 or
Adjust the default settings found in the file
Add/edit the var
LANG and save the file:
An alternative way to update the default system local without editing the file:
update-locale LANG=en_US.UTF-8 or
Reboot the server as last step.
I somehow still think TS.ChrisR is right with that statement.
How do actually start your TeamSpeak server?
Do you start the server using the startscript manually in the terminal?
As I’ve asked above already, did you setup your TeamSpeak server as service?
Without answering these questions I’m not able to go on investigate your issue.