Why can’t my Mbed Wi-Fi device roam or re-connect after being disassociated from AP?
There is a known issue in WHD v1.40.0 and v1.50.0 that prevents roaming or auto-reconnect to happen correctly. If the target Wi-Fi device is disassociated by the AP (could happen in various scenarios like when AP is being shut down or when the signal is too weak), the corresponding join event handler will be removed from WHD driver, which causes the subsequent connect status update to fail. When this happens, the roaming or re-connection will fail. To work around this defect, your application can make a join function call
(whd_wifi_join or whd_wifi_join_specific) to connect back to the original SSID when you get a WLC_E_DEAUTH_IND or WLC_E_DISASSOC_IND event.
This defect is present in the Amazon FreeRTOS version 201908-MTBAFR1941 and Mbed OS 5.14.2. This issue has been fixed in WHD v1.60.0. The updated driver will be released Amazon FreeRTOS version AFR-201911.0 and Mbed OS 5.15.