In case anybody is interested: I solved the issue. It was NOT Rom related. It was Isp / Router related.No same often happens with Whatsapp text Messages or other Fcm based Messaging Apps..they do come through, but most of the time 1-3 Minutes after they were sent (when the screen is off and the phone was in idle). As soon as i manually wake the phone they pop up instantly.
Keep up the great work - this rom is fantastic