iPhone stopped receiving notifications from some apps

I have an iPhone XR running iOS 15.2.1. Recently, I stopped receiving notifications from several apps, most importantly Outlook, which is my work e-mails, and Ring, which is my home security. Up until recently, I received notifications from these apps all the time. I still receive notifications for text, calls, Facebook Messenger, etc, but suddenly not from those 2 important apps. Those apps still work, and I can view new e-mails and Ring alerts when I go into the apps, but I am no longer notified in the home screen or lock screen, so I don't know I've received them until I open the apps to check. Nothing has changed on my end, except maybe downloading the latest iOS update. All of my general notification settings and app specific notification settings are still the same. My phone is not in the do not disturb focus or airplane mode. Scheduled Summary is turned off. I don't use screen sharing. I tried every suggested fix I have read about: turning the notifications for those apps off and then back on, turning airplane mode on and then off, restarting my phone, resetting my network settings, etc, etc, but nothing has helped. I need to receive instant notifications from these two apps. I don't know if any other apps are affected. Any help would be appreciated. I have no intentions of doing a factory reset though.