CC3220SF Launchxl :MQTT_client_server例程代理连接失败

开发板：CC3220SF Lanuchxl                                              例程：MQTT_client_server

SDK：simplelink_cc32xx_sdk_4_20_00_07

hi！你们好，我在使用 CC3220SF 导入例程 rtos/CC3220SF_LAUNCHXL/demos/MQTT_client_server 后，设置好 AP 连接的参数（本地wifi账号密码） ， 烧写进开发板后终端上总显示代理连接失败，连本地的客户端好像也连接失败了，我该如何作出调整才能连接成功呢？

终端显示：

        ============================================
           MQTT client server Example Ver: 1.1.1
        ============================================

         CHIP: 0x30000019
         MAC:  2.0.0.0
         PHY:  2.2.0.7
         NWP:  3.16.0.1
         ROM:  0
         HOST: 3.0.1.65
         MAC address: 98:84:e3:f6:61:9a

        ============================================




                 *************************************************
                    CC32xx MQTT client server Application       
                 *************************************************



Device came up in Station mode
[WLAN EVENT] STA Connected to the AP: hopetruly , BSSID: 78:11:dc:46:c5:d
[NETAPP EVENT] IP acquired by the device

Device has connected to hopetruly
Device IP Address is 192.168.31.51 

...........Connection to broker failed, Error code: -111
BRIDGE DISCONNECTION

On-board Client Disconnected
In order to reconnect local client, Reset board.

.

如果有人能帮助我，我将感激不尽！