You have created favorites in the UMC and these have disappeared after an update again
The UMC favorites are stored in the user object and can be found via univention-ldapsearch:
root@ucs:~# univention-ldapsearch "uid=Administrator" univentionUMCProperty # extended LDIF [...] dn: uid=Administrator,cn=users,dc=multi,dc=ucs univentionUMCProperty: appcenterSeen=2 univentionUMCProperty: udmUserGridView=default univentionUMCProperty: favorites=updater,udm:users/user,udm:computers/computer ,udm:dhcp/dhcp,udm:dns/dns
If the user logs on to another host, the same favorites should apply. However, if one of the modules is not available on the backup or slave, the favorites are reset (deleted).