notifications after iOS 15.4 update

Hi! I am having a problem with my iPhone XR notifications after iOS15.4 update. I receive no notifications unless I open the app (Gmail, Messenger, WhatsApp etc.). I have restarted my phone, checked the Notifications in the Settings (the apps individually, turned off Scheduled summary etc), Background App Refresh is turned on for all the apps etc, Focus mode is not turned on etc.

Also the apps (Gmail, Messenger etc) only seems to update content only after opening the app- i.e. new emails/ conversations etc appear in the app only after the app is opened.