notifications receive only when i open the app

i am receiving notifications only when I open the apps particularly WhatsApp, WeChat, Instagram, etc. background app refresh is on for all apps, every notification setting is turned on. First tried to reset location settings, then network and after all settings reset. iPhone restart, hard restart I have tried everything but none worked. But some apps work fine like default Apple apps, Snapchat and threads app. I am on latest version of every app and software. I think it might be network settings problem because from my brothers phone I tried to send message to myself but messages are not delivered like one tick only. It received only when I open the app. Same happens with every app. I am frustrated from one week. Can’t open every app always to check who is trying to communicate with me. I have arrived all solutions available online. Similar kind of problems all already listed on apple community but can’t find any solution there so posted a new.

iPhone 12 Pro Max iOS 17.4.1