Steps to reproduce:

1. Go to "Configuration" -> "Templates".
2. Click on "Items" for "Template ICMP Ping".
3. Go to "Configuration" -> "Templates".
4. Click on "Triggers" for "Template App Zabbix Server".
5. Click on any item link to go to its configuration page.
6. Click "Cancel".

Note that item list for "Template ICMP Ping" is shown. It should probably show items for "Template App Zabbix Server" instead, because it was the last template we viewed configuration for.