Correct, but this one was quite easy to find as the compiler raised the issue as the function parameters no longer matched.
Having to specify the option in the prj.conf to support dynamic BT GATT service creation was quite harder :). I had no glue the bt_gatt_service_register code was no longer linked in when the option "CONFIG_BT_GATT_DYNAMIC_DB=y"
was not set in the prj.conf file.
Thanks for the response,