Steps to reproduce:

1. Have an active agent configured and working with agent interface address 127.0.0.1
2. Set AllowKey=system.run[*] in the agent
3. In Zabbix UI, go to Alerts - Scripts and create a script:

1. 1. Name: Hostname script
   2. Scope: Manual host action
   3. Type: Script
   4. Execute on: Zabbix agent
   5. Commands: hostname
2. Go to Administration - General - Timeouts, set the Script timeout to 10s
3. Go to Monitoring - Hosts, click on the agent host and run "Hostname script"
4. Observe the results

Result:

Sometimes the script runs successfully. But most often the result is:

Cannot execute script. timeout while retrieving result for remote command

Expected:

Successful script execution is expected all the time.

Packet analysis based on the attachment "supportcase-2024-07-06.pcap":

• At 20:33:38 (frames 19-20) the proxy connects to the server and receives plain "success" as response (= no remote commands to execute anywhere)
• At 20:33:39 (frames 25-26) the proxy connects to the server and receives the command to execute on the agent (taskid 74)
• At 20:33:44 (frames 35-36) the agent connects to the proxy and receives the command "hostname" to execute
• At 20:33:44 (frames 37-38) the agent has executed the command and returned the result "ubuntutest2204" to the proxy, with result "success"
• Right after that at 20:33:44 (frames 39-40) the proxy sends the taskid 74 results to the server as "timeout while retrieving result for remote command"

--> Why does the proxy say "timeout" to the server even though the agent returned the response?