Door constantly falls off

HiI have 2 doorbells, front and rear. The one on the back of the property constantly ceases sending notifications. The device health is good and the Internet signal is always between 45 and 55. I have twice had to hard reset the device which has included removing the app from one device then use a 2nd device whilst reinstalling on original device, on the lengthy calls with ring.This is now the 6th time this has happened in the 7th months I have owned it. How do you stop it from happening?The front door is fine, I have swapped them and it just happens again no matter which device is at the rear.