Multi Data Source Zabbix

I created Variables DataSource Zabbix. I have two DataSource.
DataSource Zabbix01 have HostA.
Datasource Zabbix02 Have HostB.
If i select Multi Values DataSource Zabbix01+Zabbix02 or All option on my dashboard, i don’t see Items of HostA + HostB, but i see only items of HostA
My Grafana version is: Grafana v6.5.2 (742d165)

If i select only one Datasource Zabbix01 or Zabbix02 i see HostA or HostB.
I need to see the items of HostA+HostB
Is it a bug?

Thanks
Francesco