I have tested your demo config and was able to run the demo. Please find the logs, :
0 0 [None] FreeRTOS_AddEndPoint: MAC: 11-41 IPv4: 10.10.10.200
The following network interfaces are available:
Interface 1 - rpcap://\Device\NPF_{BE1AF62A-A518-484E-9EB7-7BD7095DCCD0}
(Network adapter 'Microsoft' on local host)
Interface 2 - rpcap://\Device\NPF_{1F8B9C8C-BE0F-4B12-9E17-DFD972793CF6}
(Network adapter 'Microsoft' on local host)
Interface 3 - rpcap://\Device\NPF_{3EB30C62-3C4C-427F-BB21-AA53A28E68C1}
(Network adapter 'Microsoft' on local host)
Interface 4 - rpcap://\Device\NPF_{4BC20A74-15F0-49D0-BE6D-DBA3A76247FF}
(Network adapter 'Oracle' on local host)
Interface 5 - rpcap://\Device\NPF_{44BB3D52-A65F-45DB-83BC-3022AA9B623D}
(Network adapter 'Microsoft' on local host)
Interface 6 - rpcap://\Device\NPF_{64BAC72F-15DD-42EF-95AD-832FC91E3D6B}
(Network adapter 'Realtek USB NIC' on local host)
Interface 7 - rpcap://\Device\NPF_{3919812B-DC0E-4F33-B5F0-A501573E1C6A}
(Network adapter 'TAP-Windows Adapter V9' on local host)
The interface that will be opened is set by "configNETWORK_INTERFACE_TO_USE", which
should be defined in FreeRTOSConfig.h
Attempting to open interface number 6.
Successfully opened interface number 6.
DHCP-socket[11-41]: DHCP Socket Create
1 1201 [IP-Task] prvCreateDHCPSocket[11-41]: open, user count 1
vDHCP_RATimerReload: 250
2 1203 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTDemoTask:570] ---------STARTING DEMO---------
3 1203 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTDemoTask:576] Waiting for the network link up event...
4 1471 [MAC_ISR] Bounced back by WinPCAP interface: 00:11:11:11:11:41
vDHCPProcess: offer 192.168.0.101 for MAC address 11-41
5 1831 [IP-Task] vDHCPProcess: offer 192.168.0.101 for MAC address 11-41
IP Address: 192.168.0.101
6 1831 [IP-Task] Subnet Mask: 255.255.255.0
Gateway Address: 192.168.0.1
7 1831 [IP-Task] DNS Server Address: 192.168.0.1
prvCloseDHCPSocket[11-41]: closed, user count 0
8 1831 [IP-Task] vDHCP_RATimerReload: 21600000
[INFO] [MqttMutualAuth] [prvConnectToServerWithBackoffRetries:741] 9 2203 [DemoTask] Creating a TLS connection to a2vtd9m5hzbrcl-ats.iot.us-west-2.amazonaws.com:8883.
10 2231 [IP-Task] ipARP_REPLY from 192.168.0.1 to 192.168.0.101 end-point 192.168.0.101
DNS_ReadReply returns -11
11 7203 [DemoTask] prvIncreaseDNS4Index: from 0 to 0
DNS[0x4B0F]: The answer to 'a2vtd9m5hzbrcl-ats.iot.us-west-2.amazonaws.com' (44.239.31.83) will be stored
12 7291 [DemoTask] FreeRTOS_connect: 43565 to 44.239.31.83:8883
[INFO] [SocketsWrapper] [TCP_Sockets_Connect:189] 13 7491 [DemoTask] Established TCP connection with a2vtd9m5hzbrcl-ats.iot.us-west-2.amazonaws.com.
14 9011 [DemoTask] [INFO] [MbedtlsTransport] [tlsHandshake:613] (Network connection 0199FE2C) TLS handshake successful.
15 9011 [DemoTask] [INFO] [MbedtlsTransport] [TLS_FreeRTOS_Connect:784] (Network connection 0199FE2C) Connection to a2vtd9m5hzbrcl-ats.iot.us-west-2.amazonaws.com established.
16 9011 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTDemoTask:596] Creating an MQTT connection to a2vtd9m5hzbrcl-ats.iot.us-west-2.amazonaws.com.
17 9831 [DemoTask] [INFO] [MqttMutualAuth] [prvCreateMQTTConnectionWithBroker:862] An MQTT connection is established with a2vtd9m5hzbrcl-ats.iot.us-west-2.amazonaws.com.
18 9831 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTSubscribeWithBackoffRetries:923] Attempt to subscribe to the MQTT topic fish_iot/example/topic.
19 10371 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTSubscribeWithBackoffRetries:930] SUBSCRIBE sent for topic fish_iot/example/topic to broker.
20 10411 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTProcessResponse:1072] Subscribed to the topic fish_iot/example/topic with maximum QoS 1.
21 12411 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTDemoTask:610] Publish to the MQTT topic fish_iot/example/topic.
22 12991 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTDemoTask:616] Attempt to receive publish message from broker.
23 12991 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTProcessResponse:1053] PUBACK received for packet Id 2.
24 12991 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTProcessIncomingPublish:1108] Incoming QoS : 1
25 12991 [DemoTask] [INFO] [MqttMutualAuth] [prvMQTTProcessIncomingPublish:1119]
Incoming Publish Topic Name: fish_iot/example/topic matches subscribed topic.
Incoming Publish Message : Hello World!
This is the commit with which I have run the tests.