Systemd unit only applies User, Group & RuntimeDirectoryMode settings on service restart

I'm using Fedora 28 x64 on a VPS. I've setup postfix as send-only mail server with OpenDKIM for signing outgoing emails. Postfix connects to OpenDKIM via unix socket setup on

/run/opendkim/opendkim.sock

Permission for

/run/opendkim/

is as follows

------.  2 opendkim opendkim   80 Jul 13 00:05 opendkim

For Postfix to connect to the OpenDKIM milter, I've changed

to

in the OpenDKIM unit file and added

=0750

. Here's the entire

.service

file. Location:

/usr/lib/systemd/system/opendkim.service

[Unit] Description=DomainKeys Identified Mail (DKIM) Milter Documentation=man:opendkim(8) man:opendkim.conf(5) man:opendkim-genkey(8) man:opendkim-genzone(8) man:opendkim-testadsp(8) man:opendkim-testkey http://www.opendkim.org/docs.html After=network.target remote-fs.target nss-lookup.target syslog.target [Service] Type=forking User=opendkim Group=postfix PIDFile=/run/opendkim/opendkim.pid EnvironmentFile=-/etc/sysconfig/opendkim ExecStart=/usr/sbin/opendkim $OPTIONS ExecReload=/bin/kill -USR1 $MAINPID RuntimeDirectory=opendkim RuntimeDirectoryMode=0750 [Install] WantedBy=multi-user.target The issue I'm facing is that the

,

,

values are only applied when I restart the OpenDKIM service manually. OpenDKIM is enabled to run on system boot via

enable opendkim

. But after rebooting the VPS, the directory permissions are the same.

------.  2 opendkim opendkim   80 Jul 13 00:05 opendkim

I've to run

restart opendkim

for the permissions to change to

-x---.  2 opendkim postfix   80 Jul 13 00:05 opendkim

Any idea why this happens? Anything I'm missing here?