Door sensor disappeared and alarm went off

My contact door sensor stopped working, it randomly disappeared from my app and then one night my alarm went off in the middle of the night and I thought someone broke in. I noticed in my notifications that it was set off by my garage door sensor which is the one that in fact disappeared. So now that I try to reconnect it the sensor just keeps blinking and I’m not able to connect it back. I am extremely frustrated with this as it caused a false alarm for my house and had the police come for no reason and scared my family and I and I have a 1yr old. I need Ring to send me a new sensor and I can send my back to you for diagnostic testing so you can figure out why this happened and doesn’t happen again.