So I just got the S21U today, and everything is wonderful so far, but could not figure out how to make sure whatsapp stays running in the background....
Background usage limits = put unused apps to sleep is OFF
sleeping apps/deep sleeping apps/ never sleeping apps is 0
I went into Optimise Battery Usage, and made sure NONE of the apps or services are enabled (so no optimization for anything!!!)
I even tried, enabling Battery optimization, and then adding whatsapp to NEVER sleeping apps. (did not change the behaviour)
"Allow background activity is selected" .. (I tried turning on and off Put unused apps to sleep) IT is now off, as it made no difference.
On all my other phones this seems to be working, never even had to do any of these settings.
The only thing that makes sense is Power Saving MODE OFF! but the description udner it...
Learning usage patterns...
Background network usage, syncing, and location checking will be limited and motion smoothness will be changed to standard.
I work all day and I need to be online on WhatsApp, what am I going to do, set the screen to never turn off so that the device is awake 24/7?
Same here, I turned off all sleep apps, adaptive, battery/power, DND, and background limit settings. Whatsapp still goes to sleep in a little while after screen is turned off. From that point on, I stopped getting notifications/messages/calls (also GPS location sharing) until I wake the screen up.
Samsung please fix it ASAP! The phone become unusable if I can't get notification that I needed in real time.
Didnt work for me
Does this happen while connected to Mobile Data only or also on Wifi?
Battery lasts 26 hours for you with the Adaptive Battery feature turned off?
I am experiencing this issue and finding that I do not get WhatsApp calls and texts when the screen goes off. The phone is stationary most of the time with all battery optimization turned off, mobile data turned off and wifi on. I guess if I walked about with the phone in my hand all the time it would work ok Having read several other posts re this problem I suspect that the wifi connection process is being put to sleep and there is no setting to prevent this from happening. As mentioned by OP this is quite a serious problem and needs fixing.
If I'm on Wifi I don't have this problem.
This is a sh*tshow anyway. Samsung is silent and we are left we an half working app.
If their idea of making the battery last longer is to stop app from working, well ***** done.