My iphone notification stopped working after a recent ios update.

After installing a recent IOS update (15.4.1) on my iPhone (XR), I stopped getting notifications. I checked notification settings for app are on(lock screen, notification center, banners). Focus is off. But I don't receive notices. Not from camera, doorbell, vpn app (Duo Mobile).

Perhaps related is that for my work VPN, I formerly received a notice with accept or deny buttons on logging in. However, since the problem started, I don't get the notice and the buttons don't appear until I put the app in the background and then restore it to the foreground--ie, it seems to need to poll for the notice on a "refresh".

I've also tried toggling the notifications settings and have tried power cycling iphone, but to no avail.

Furthermore, I have installed updates for the apps, as well, trying to resolve issue.

However, I seem to get Messages notifications