Ring Door view Cam - "Footage Unavailable"

Hi All Im after some help with my Door View Cam. Ive had the unit around a month now and overall its pretty good. the issue im having is that at random points in the day in the timeline, im getting Footage unavailable. Now this could miss a single 15 min period of the day or in some cases hours of the day and its completely random, mainly happens in the day but happens at night also. Now I've looked though various other topics and on other products network settings seem to be common thing. Even though i cant find any settings specific to my product, I've followed them anyway. - Door cam is on a static IP - Its now in the DMZ allowing all ports open. - It is in line of sight with my wireless router. - No "green ethernet" or energy saving options enabled. Wireless strength is fairly solid at -45rssi Ive attached a photo screen grabs of the app to show you. Hopfully someone can help.