Inconsistent doorbell and sensor notifications

So, have a wireless video doorbell and three door sensors in my home setup. Worked well for good few months, but lately the audio notifications to my phone have been quite inconsistent. Should get a beep on my phone each time a sensor is opened or closed. Think OK at present, but is very inconsistent. Have noticed that when I go to settings /notifications screen, sometimes there are 2 “motion” sensors listed and sometimes only 1? Don’t understand why this is. If anything should there be 3 given sensors on three doors? Also my camera keeps going offline and only way to wake it is by unmounted it and attaching it via cable to the homebase. Then typically after a couple of days it goes offline again. Getting pretty frustrated with a system I was initially quite a fan of…Any advice most welcome.