@robayzma `gcm` for Android in registration call payload is present due to legacy reasons. Campaign uses fcm APIs in the background whether `gcm` or `fcm` is sent in the payload. For the incongruent behavior you mentioned regarding the push notifications between workflow behavior and transactional message, please reach out to the customer care https://helpx.adobe.com/contact/enterprise-support.ec.html to open a ticket on Campaign.