Observation Details
Focusing the tabs "Bereit für ein neues iPhone?" & "Bereit für den Wechsel zum iPhone?" by assistive technology will automatically select the tab. This results in behavior, that the first tab can be selected by assistive technology but moving to the main content is not possible, as navigating through the page will automatically select the second tab.
Remediation Notes
Ensure, selecting tab by assistive technology like screen reader is done by clicking the button instead of focusing it.