Ring 3 delaying notification

My Ring 3 has suddenly decided to delay notifications by upto 30 seconds. It has also stopped recording events and giving me a live stream. I have deleted and reinstalled the device. My internet speed if 76Mb down 20Mb up and works for all other systems. WiFi access point is within 10 feet and has no issues.
Does anyone have any ideas as to the problem and a fix?

@SimonSmith Has anything in your setup changed at all such as a new router, router being moved, any new devices etc?

No. Everything has been the same for ages.