Samsung A21s - system software update unexpectedly used mobile data

[RicRoller]

Got an A21s on EE PAYG; a couple of nights ago it auto-downloaded a system software update, but unexpectedly did so using mobile data (I turn my broadband router off overnight - however I believed that I had set up the phone such that the update should only have been auto-downloaded via Wi-Fi).

• Data Saver is turned ON (however in the list of apps allowed/disallowed to use mobile data in the background, "Software update" does not appear there, either as a user app or as a system app)
• The software update is configured to auto-download over Wi-Fi (Setings -> Software update) - the toggle is ON)

I can see in the phone's record of data usage (Settings -> Connections -> Data usage -> Mobile data usage) that the app "Software Update" used 124MB of mobile data; this usage is also shown if I log in to the MyEE app (and has come out of my active PAYG pack's data allowance).

But I do notice that the software update "Auto-download over W-Fi" setting is vague, and implies that the phone could also download the update over mobile data if it thought that the usage was free (zero-rated) by the network provider. The text shown on the screen underneath the toggle is:

Download software updates automatically when connected to a Wi-Fi network. Depending on your service provider, updates may also be downloaded using mobile data without any additional charges. You'll still be able to use your phone during the download.

So I am guessing that the phone may have (erroneously?) decided (or been told by the EE network) that the download over mobile data would be zero-cost - and just went ahead and did it!

So what I would like to know is whether there is/what setting(s) to use such that the phone is still capable of auto-downloading those potentially important system software updates, but would never automatically download them using mobile data.

Thanks 🙂

[354-]

What did the Samsung support team have to say for the feature you are looking for, did they point you to the right setting? 

[wardi]

Go into Google play, click the 3 bars in top left corner then 'settings'.  Under 'app download preference' choose 'over WiFi only'.

It is also a good idea to put your phone into airplane mode overnight to avoid data use, not to mention unwanted calls or texts. 

I've not had any problems since I employed this setting.

[RicRoller]

@354-

Thanks for your comment; I have not contacted any support person (the observations were all made from the phone itself). And so far I haven't found anything "interesting" on Google either...

@wardi

Thanks for the tip - however I believe the system software update was pushed from Samsung, and did not come via Google Play. However in the Google Play settings the download settings were probably sensible.

App download preference = any network (I think this would only apply to new apps, not updates to already-installed ones). But I'll try changing it to "Wi-Fi only" to see if there's any difference... And "auto-update apps" was already set to Wi-Fi only

I use scheduled "do not disturb" overnight, to me airplane mode seems a bit drastic as it would prevent receiving an emergency call!

Hoping that I can find the optimum setting before Samsung release Android 11 for the A21s; that's one system software update I don't want to be downloading over mobile data! For now I've turned the system software auto-update off (hoping that I'll still get a notification when an update us available)

Thanks 🙂

[354-]

@RicRoller, ah ok. Hope you find the setting(s), nobody likes unexpected data consumption!