Intermittent connection issues

Intermittent failure to make notifications on different devices. I bought my ring door bell with an Amazon Alexa show, I've since bought an Alexa dot and another Alexa show. My doorbell sometimes makes notifications on some of my Alexa devices and sometimes doesn't, the same happens on my phone. I've connected it to 2 mobile phones and just doesn't work on one of them, no notification whatever I do, unless I load the app on the phone and then a couple of minutes later it starts ringing for every notification that's happened since the last time I opened the app. The ring site just says to check the doorbell connectivity to the WiFi, but I can have both mobile phones in my hand both connected to my home network and one will ring while the other one won't. Sometimes it just decides not to notify me on any device. If I mute the notifications on the app, I find that a random Alexa device in my house will still notify me of motion detections, if I then open the ring app on my other phone, it says the motion alerts are still on even though they are showing as off in the app on the other phone. I have had to put my old standard doorbell up because I am missing so many deliveries. Any help would be soo appreciated