Zabbix IT Services feature set

[Graham Johnston <johnstong () westmancom com>]

Hi,

We have the Zabbix IT Services (running on Zabbix 3.2) configured for some test groups.  It usually returns good data 
but occasionally it seems that one service group or trigger will get stuck in an alerting state and provide an 
incorrect SLA.  This can occur if the trigger has changed to a problem state and then back to OK but the IT services 
doesn't reflect that change.  It will occur where the top level group will show as having 100% problem time and the sub 
groups and items either have no problem time or such a small amount that it wouldn't indicate 100% problem time.

We have it built with some groups under root, some sub groups and items and the items will have a trigger associated 
with those items.  We followed this article to the best of our knowledge: 
https://www.zabbix.com/documentation/3.2/manual/it_services
 
For Example: 
|Data Center 
|-Core1
|--Core1 - ICMP - Trigger
|-Core2
|--Core2 - ICMP - Trigger

Each subitem is a child of the item above it.  We haven't configured any dependencies to any other groups or items.
My question is, has anyone gotten the Zabbix IT Services to work correctly?  Is there a trick to getting it to work, 
some configuration we are doing incorrectly?

Thanks,
Graham