WhatsApp stuck on “Connecting”

Hey,

Recently, I bought a brand new iPhone 14 Pro Max after years of using an Android device.

Since the transferring of all the data I have troubles mainly with Whatsapp.

First, every time I open the app, it is showing "connecting" and just after a few very long seconds, all the messages show up. even if only one message is waiting for me and I haven't closed the app. At the same time, the notifications from WhatsApp are updating normally.

Second, every time I send a message, the typing is very slow and sometimes stuck, and after I tap the "send" button, it’s stuck for a few seconds until it jumps to the chat and sends.

I'm also experiencing connection problems with the weather (it is not showing any data for a few seconds, both in the app and the widgets) and other apps that usually work good.

I checked a lot of times all kind of settings (for example "Background App Refresh"). I deleted apps and especially WhatsApp at least 10 times. I contacted them without getting any working solutions. My friends have the same phone and have no problems with it. I tried all the solutions that I could find on the internet. I even made a factory reset as my last choice.

I'm having this problems everywhere. At home and at work. On Wi-Fi and on cellular (5G/4G).

I have the latest available iOS.

I'm hoping someone is aware of the same problems and/or has solutions.