Custom legato application doesnt start from boot

Hi There ,
I am trying to add a custom legato application whose binary file is called in the adef file and both the binary and .adef file are copied in legato-18.09.0/apps/platformServices in order to add the application to my custom system/framework I have added following line in default.sdef file
$LEGATO_ROOT/apps/platformServices/APP_NAME
But with the above additions i just have the application copied into the framework but the application doesn’t start from boot even though i have mentioned start:auto in the .adef file . {with manual input “app start APP_NAME” the application works well}
Can someone help me in overcoming this issue ??
Legato version used : 18.09.0