Description:

Item mqtt.get must be configured as active check. When mqtt.get is configured via zabbix agent it's status is "Not supported". If you change "Zabbix agent" to "Zabbix agent (active)" item status stays "Not supported" untill item receives a message.

Precondition:

Install message broker. Used Mosquitto for this scenario

Steps to reproduce:

1. Create host
2. Create new item:
   1. Type: Zabbix agent
   2. Key: mqtt.get[localhost,"test"]
3. Observe item status and error in screenshot: 
   
4. Go to item. Change item Type to "Zabbix agent (active)"
5. Wait for 2 minutes
6. Send a message to item

Result:

1. Item stays with status "Not supported" and error message.
2. Item status changes to "Enabled" only after item receives a message.
   

Expected:

Item should change status to "Enabled" after Type is changed to "Zabbix agent (active)"