The DN of the portal sent to the portal frontend is incomplete, therefore the JS part will not render the portal entries.
Fixed by resyncing all portal listeners in univention-portal 2.0.2-7A~4.3.0.201809261555
Changelog&Advisory: OK Fix works: OK If someone updated before that fix, the order of service and admin category will be reversed.
<http://errata.software-univention.de/ucs/4.3/255.html>