Wifi turning goes to sleep despite settings to keep it on

[AC Question]

I have noticed this with the new android 6.0 marshmallow update. Wifi turning off despite "keep wifi on during sleep" set to "always" on Nexus 5 phone. When I power on the phone I see it quickly re-connect WiFi. But why isn't it already on? I've also noticed that my apps are not syncing very often when the phone is left in sleep.

Anybody else seeing this behaviour? I'm all for battery savings, but if it's plugged into power & WiFi is available, why is it not just keeping it on??

Settings:
"keep wifi on during sleep" set to "always"
settings-->location-->menu-->scanning -> set to "Wi-Fi scanning"
Battery-->Battery saver--> Off

 

[Kouuf]

If you haven't already found a solution, restarting my phone worked for me. I have a galaxy j5 prime with android marshmallow and it worked miraculously.

 

[boomerfss]

This has been driving me nuts for over a year. I stream music in HIFI so it chews up data.

This works for me...Go to "Battery and power saving"...Battery usage"..."Battery optimization"..."Ignore optimization"...then select individual apps you want to run when the phone is asleep. For me the App I want running on WIFI is Sonos as I am streaming music.

Now my WIFI is always on when I am using Sonos, even after a long period of time.

 

[voodoofox]

I have FINALLY found a wifi keep alive app that works very well with Marshmallow:
Free: https://play.google.com/store/apps/details?id=pl.mariobile.bestwifikeeper&hl=en
Pro ($1): https://play.google.com/store/apps/details?id=pl.mariobile.bestwifikeeper.pro&hl=en

They updated it to add marshmallow support and it really does support it in that my wifi stays on, even if the connection is idle, all day at work now. Which is great because my VPN stays connected as well, which is what I really wanted.

I don't like how marshmallow jumps on LTE when wifi is disabled. After using up over 3GB in a week like that, I got into the habit of disabling mobile data when i get to work, and enabling it when i goto lunch and disabling it again when i get back and now I don't have to.

Awesome little app, recommended. Unless battery life is critical for you – but at work my phone is often on charge anyway.

I also like wifi keepalive (https://play.google.com/store/apps/details?id=com.roy.wifimonitor&hl=en) but best wifi keeper is a bit better. I found wifi keepalive had lots of errors if connected to a VPN.

I know it's an old thread, but this app helped me.
I am on official 5.1.1 android version (so no battery optimization options here).

I've been testing this app for about an hour and wifi is still working (I am testing by keeping a continuous ping form my computer to android wifi's IP).

So far so good.
Thanks for the recommendation!

 

[alexceltare2]

I think this is a feature, and a really bad one at that, to conserve power during sleep by always turning the WiFi scanning and connecting off. I've fixed my issue by modifying the /system/csc/others.xml and adding the following string in the list:

<CscFeature_Wifi_SupportAutoReconnect>TRUE</CscFeature_Wifi_SupportAutoReconnect>

on my Samsung phone. You can modify the file by rooting, magisk or TWRP. Remember that these methods may brick your device & warranty if done incorrectly.