Steps to reproduce:

1. Go to Configuration -> Hosts -> Zabbix server trigger list
2. Click on one of the triggers to open update form
3. Go to "Dependencies" tab
4. Press "Add" button
5. Check selected host group and host

Result: is selected first host group and host from list
Expected result: is selected Zabbix servers group and host Zabbix server

If can't repeat, firstly do this all steps with another host or template