Google two-step verification doesn't want to work. Pops up, I approve and nothing happens

Phone is a Samsung Note 9 SM-960F model. The phone is running Android 10. And I never experienced this problem on any other phone, model or Android version before. Basically I am logged into my Google account. Every Google service works great. Except two-step verification. - I get the "notification" in Chrome for example when I sign in on a new PC. All great. - The phone makes a notification sound, the two step verification pops up. - I tap "Yes", I get a toast notification "Approved".... and nothing happens. What could cause this and how could I fix this?