Contact Sensor Disappeared 1st Gen with No Notification! Very Disappointed

Ring Community,I noticed that 2x of my Ring 1st Gen contact sensors on doors just completely disappeared from my alarm base station device list.I can't pinpoint exactly when it may have occurred but this is a huge vulnerability as if I didn't notice someone could have broken in through these doors without me knowing. I recommend Ring alarm to all friends and family and this is extremely disappointing.I was able to put in a new battery in both and re-pair via QR Code scan. I am hoping it was just some kind of odd glitch as both sensors are working normal at the moment.If the battery was low the system should notify me or even stay listed in the device list, but the fact that it completely just removed itself doesn't sit right with me.I wanted to create this topic to not only inform the Ring community / Ring Development of what happened but see if it happened to anyone else. Do I need to check my alarm base station device list weekly and run an audit check on every sensor to make sure it still exists?Should I swap out all my 1st Gen sensors with Second gen? Is there a known firmware or software bug we should be aware of?I appreciate your help on this matter.SignedA Big Ring Alarm Fan who is currently concerned but also disappointed.