systemd service will not start automatically at boot-up

Question

I've been struggling to solve this for 2 or 3 days now. I am using Yocto to customize a Linux build. I have a systemd service called app2.service as below.

[Unit]
Description=app2 
ConditionPathExists=/app
After=network.target uncrypte_app.service uncrypte_data.service 

[Service]
Type=simple
WorkingDirectory=/app
ExecStartPre=/bin/rm -f /var/run/appd.pid
ExecStartPre=/app/provisiondevice && /storage/revertupdate
ExecStart=/app/appd start
ExecStop=/app/appd stop
RemainAfterExit=yes
Restart=on-failure

[Install]
WantedBy=multi-user.target

Below is the bottom of my .bb recipe file.

SYSTEMD_SERVICE_${PN} = "app2.service" is the Yocto equivalent of systemctl enable app2.service

FILES_${PN} += "app"
FILES_${PN} += "/persist_storage \
            /storage \
"
FILES_${PN} += "${sysconfdir} \
           ${systemd_unitdir}/system/app2.service \
"
inherit systemd

SYSTEMD_SERVICE_${PN} = "app2.service"

However, when my device starts , the service does not.

When I check the status of my service with systemctl status app2.service , I get the following

● app2.service - app2
 Loaded: loaded (/lib/systemd/system/app2.service; disabled; vendor 
preset: enabled)
   Active: inactive (dead)**

I cannot understand this. When I then manually enable it with systemctl enable app2.service , it works fine.

It should be automatically enabled the way I have it specified in the recipe file. I'd appreciate any help with this.

Also adding the following to the bottom of my recipe file doesn't work either :

SYSTEMD_AUTO_ENABLE_${PN} = "enable"