MQTT Connect failing with error (28) 6 on Ewon Flexy 205

Hi,

I'm trying to connect my Ewon Flexy 205 to a local MQTT broker (Mosquitto, running on a PC on the same LAN) using a BASIC script, but the connection consistently fails.

Device details:

• Model: Ewon Flexy 205
• Firmware: 14.8s0 (#2633)
• S/N: 2049-0404-24

Script used:

Mqtt "Open","EwonClient","192.168.1.7"
Mqtt "SetParam","Port","1883"
Mqtt "Connect"

Error received:

Operation failed (28) 6 : Mqtt "Connect"

What I've already checked/confirmed:

• Flexy is connected to WiFi with a valid local IP (192.168.1.18)
• Internet connection wizard test passes (both WAN and Internet connection show green)
• Mosquitto broker is confirmed running and listening on 0.0.0.0:1883 (verified via netstat)
• Windows Firewall inbound rule added for port 1883
• Raw TCP connectivity from the Ewon to the broker's IP:port works (tested using OPEN "tcp:192.168.1.7:1883,5" FOR BINARY OUTPUT AS 1 — no error)
• allow_anonymous true is set in mosquitto.conf

Despite all of this, Mqtt "Connect" fails every time with the same error. Could you help me understand what error code (28) 6 specifically indicates, and what else I should check?

Thank you,

deep sawant