Systemd errors of missing file “No such file or directory” inspite of file being present

The contents of my service file srvtemplate-data-i4-s1.conf is

[Unit]
Description=test service for users
After=network.target local-fs.target

[Service]
Type=forking
RemainAfterExit=no
PIDFile=/data/i4/srvt.pid
LimitCORE=infinity
EnvironmentFile=%I
.
.
.

[Install]
WantedBy=multi-user.target

I am starting my service as follows passing it an environment file but it fails with error as below.

# systemctl  start srvtemplate-data-i4-s1.conf@-data-i4-env.service
Failed to start srvtemplate-data-i4-s1.conf@-data-i4-s1-env.service: Unit srvtemplate-data-i4-s1.conf@-data-i4-env.service failed to load: No such file or directory.

The files are actually present

# ls -lrt /usr/lib/systemd/system/srvt*
-rw-r--r-- 1 root root 815 Dec 13 07:31 /usr/lib/systemd/system/srvtemplate-data-i4-s1.conf@.service

# ls /data/i4/env 
/data/i4/env

# cat /data/i4/env 
SRV_CONF="/data/i4/s1.conf"

But systemd not able to find the files.

When I do systemd reload and then fire the ablove start command it works fine.

systemctl daemon-reload

But still why is systemd not able to find the files and what can I do so that start command succeeds without firing the reload command?