The TV Auto Power On feature is not working when using a smartphone or tablet.

When the TV Auto Power On feature is enabled, it will let you control the TV power from your connected device with BRAVIA® Sync Control function. This feature is available for HDMI® Consumer Electronics Control (CEC) devices only. Mobile High-Definition Link (MHL®) devices such as smartphones, tablets and other mobile devices do not support this feature.

NOTE: As shown on the example image below, the TV Auto Power On feature is available when BRAVIA Sync Control is On.