server – Apache2.service: Failed with result ‘signal’

Why does my Apache server keep failing once in a while in my Ubuntu cloud server? For example, I will get this error when it fails:

apache2.service: Failed with result 'signal'.

The entire failed status:

‚óŹ apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
     Active: failed (Result: signal) since Mon 2021-01-25 02:30:02 CET; 4h 6min ago
       Docs: https://httpd.apache.org/docs/2.4/
    Process: 180480 ExecStart=/usr/sbin/apachectl start (code=exited, status=0/SUCCESS)
    Process: 256217 ExecReload=/usr/sbin/apachectl graceful (code=killed, signal=TERM)
   Main PID: 180495 (code=exited, status=0/SUCCESS)

Jan 23 00:00:01 ubuntu-2gb-fsn1-1 systemd(1): Reloading The Apache HTTP Server.
Jan 23 00:00:01 ubuntu-2gb-fsn1-1 systemd(1): Reloaded The Apache HTTP Server.
Jan 24 00:00:01 ubuntu-2gb-fsn1-1 systemd(1): Reloading The Apache HTTP Server.
Jan 24 00:00:01 ubuntu-2gb-fsn1-1 systemd(1): Reloaded The Apache HTTP Server.
Jan 25 00:00:01 ubuntu-2gb-fsn1-1 systemd(1): Reloading The Apache HTTP Server.
Jan 25 00:00:02 ubuntu-2gb-fsn1-1 systemd(1): Reloaded The Apache HTTP Server.
Jan 25 02:30:01 ubuntu-2gb-fsn1-1 systemd(1): Reloading The Apache HTTP Server.
Jan 25 02:30:01 ubuntu-2gb-fsn1-1 systemd(1): apache2.service: Control process exited, code=killed, status=15/TERM
Jan 25 02:30:02 ubuntu-2gb-fsn1-1 systemd(1): apache2.service: Failed with result 'signal'.
Jan 25 02:30:02 ubuntu-2gb-fsn1-1 systemd(1): Stopped The Apache HTTP Server.

Any ideas?