Ionut here with Okta's Customer Support Team, thank you for reaching out to us.

If Okta Verify Push Authentication does not work, but entering the 6 digit token works, then check the following:

1. Ensure you have a stable Network Connection or Mobile Data connection by opening your mobile browser and navigating to your organization's Okta website. 
2. Check that Push Notifications are enabled for Okta Verify in your Phone Settings.
3. Confirm that your device Date and Time is set to Network (or Automatic). 
4. Reboot your device by powering off completely and then powering back on.
5. Ensure the device is not Jailbroken, does not have a custom security layer or Mobile Device Management (MDM) profile, and that other Applications that could be interfering with delivery of notifications. 
6. Reinstall the Okta verify app.

If the above steps fail to resolve the issue, we recommend opening a Support ticket so we can further investigate.