My Wi-Fi works in background (even when my phone is in Airplane (offline) mode) and drains battery. I checked Battery usage chart (Settings/Battery/Battery usage/History details) and saw that some proccess wake Wi-Fi after some time when phone is inactive and in Airplane mode. History details of Battery usage show that (after waking up) Wi-Fi stayed turned on even my power switch is disabled.
I have that problem since last update released in september. "Keep Wi-Fi on during sleep" option is disabled (choosed "Never (increases data usage)"). Also Viber's "Wi-Fi - sleep policy" option is disabled (choosed "Viber will use device's Wi-Fi sleep policy").
Can someone help me to solve this problem?
Phone model: Samsung Note 4 (N910C)
Android version: 6.0.1