Hello roelfk7,
It looks like when you try to verify your account on your iPhone 8 you receive an alert that the verification failed due to an incorrect Apple ID/password, however, you're able to log in on other devices without an issue. We know how important it is to be able to log in to your device and download and update apps. You've come to the right place for help.
Let's start with checking another network from your device. If you have another Wi-Fi network you can connect and see if you receive the same message. Should you have the same issue we'll want to restart your iPhone:
Restart your iPhone
If you notice the same verification message after those steps reach out to our billing team using the link below so they can verify your account details:
Get Support
You can choose Apple ID to be connected to them.
Have a good day!