@VishalMakhijani 

Using Access Control a new device will not be allowed on the network unless it's in the whitelist.  A whitelist is an implicated deny all clients not on the list.  Additionally with Android and Apple devices now having a built-in MAC address spoofer Access Whitelist will require constant updating each time the MAC on your device is spoofed. I would recommend disabling the Access Control List, at least temporarily, and if the phone is allowed access you will know it has to do with Access Control and likely this MAC spoofing feature on your device.