The sectors 1-4 are displaying only black screens and the message 'Display blanked' in Live view mode on the web page of the camera.
For the other sectors, the live video can be seen without any issues.
This happens when certain sectors are blanked in the camera configuration.
Therefore, you have to remove the blanking:
See also section 5.12 from page 38 for reference: https://resources-boschsecurity-cdn.azureedge.net/public/documents/AD_IP_starlight_7000_Operation_Ma...)