Why doesn't my Nexus 7 synchronize since Android 6?

Question

Normally, Wifi is deactivated on my Nexus 7 to preserve battery. I'm mainly using it to read and watch videos when I'm commuting so I don't have Internet most of the time when I'm using it.

I'm using Tasker to switch WiFi on between 5AM and 5.10AM so my tablet can synchronize everything once a day. This worked perfectly before: in the morning, I have all current emails and Apps are updated frequently.

Unfortunately, this doesn't work with Android 6 anymore. If I'm correct, WiFi does switch on, but it doesn't connect to the wireless network. Maybe this has something to do with the new battery saving techniques, if the screen is off, WiFi is not actually connected.

I tried to extend the period by 5 minutes and added another task in tasker to force a connect, also doesn't work.

Does anyone experience this behavior too? Any ideas on how I can force the tablet to synchronize everything once a day even if the screen is off?

Thanks

Update: This night, I had my tablet plugged in and surprisingly, synchronization worked! I found an option in the advanced WiFi setting to keep WiFi active always or only when plugged in. This setting is on always on mine, so that shouldn't be the issue. Any other ideas?

Answer 1

Meanwhile, i can answer my own question. Found a description from Tasker that explains and solves the problem here http://tasker.dinglisch.net/userguide/en/androidpowermanagement.html

The important part for my Nexus 7 with Android 6:

The location of the setting may vary per device, but a common method is to launch the Android Settings app, select Apps, click the cog icon top-right, then Battery optimization. Click All apps, then Tasker, then Don't optimize.

Didn't know this menu, good to know for other apps too.