Cannot connect anymore to camera/doorbell

A few weeks ago we installed our new Ring Pro doorbell + camera.Sometimes our Wifi-router from Ziggo looses connection to internet, which may have happened this time overnight. Normally the ring system still keeps working, but this time not... After this, I was able to reconfigure the Chime. But not the Ring camera/doorbell, which now gives problems:-the lamp is rotating fast as expected-a voice says "ready for configuration", but if I try to connect again via my (Android) mobile's Ring-app, it tells that no device is found - which was just working well few weeks ago. So I cannot setup the Ring anymore. What can I do now?