Notifications are not working for all devices

For about 3-4 weeks now, I can hardly receive any notification via my Ring app. Only once in a while. By once in a while I mean maybe for one or two hours in a week I can receive notifications. And not only I can not receive camera motion alerts, I cannot receive doorbell chime either on my phone. This is not a permission or configuration problem. Because once in a while, it will just suddenly works, maybe for one or two hours, and then it will stop working again, and it does not work 99% of the time. I have checked again and again, my phone allows Ring notifications, and inside of Ring app, all cameras/door bells are configured with "Motion alerts" enabled. Not sure if this is backend server problem or app side problem. My cell phone is Samsung Galaxy S21. The quality of the Ring software is just awful and I am so frustrated.