I did have many cases where the Yun never reconnect. To solve this I made a script that runs in the backgound that checks the Wifi link, and if broken will explicitly reconnect. See WLAN issues - Arduino Yún - Arduino Forum
I did have many cases where the Yun never reconnect. To solve this I made a script that runs in the backgound that checks the Wifi link, and if broken will explicitly reconnect. See WLAN issues - Arduino Yún - Arduino Forum