Friday, July 26, 2019

Broken iOS Cellular Data Switch

It’s late in the iOS 12 cycle, but with iOS 12.3.1 I’m seeing a resurgence of an old bug from the iOS 7 days. Specifically, iOS is letting apps such as OmniFocus and Overcast use cellular data, even though I have them unchecked in Settings > Cellular. I’ve had this off for years for certain apps in an effort to reduce my data usage. OmniFocus, in particular, can use more data than all my other apps combined, if I let it, and it’s unnecessary because I’ve already synced the latest data via Wi-Fi before leaving my Mac.

Of course, the reason I noticed this is that my cell plan ran out of data two weeks early, and I never run out of data. The first thing I did was check Settings, and there were all the data-using apps, at the top of the list, despite being unchecked. (I also confirmed that Wi-Fi Assist was off and that the problem persisted after rebooting.)

Omni’s support confirmed that the app has no control over this—it couldn’t override the OS setting even if it wanted to. But they had a helpful suggestion: toggling cellular data on, restarting the phone, toggling it off again, and restarting again. I hate this sort of voodoo, but it indeed seems to have worked.

Update (2019-07-29): Marco Arment:

This is killing me. I get reports every day from people saying Overcast is using cellular data despite it being turned off in system settings.

I’ve checked back with many of them, and Wi-Fi Assist is disabled, so it’s not that.

My app is getting the blame for a clear iOS bug.


Have had the same. 20 GB Data Volumen used up within a few hours over night.

Dan Merfeld:

I picked a bad time to go over seas! I was hit by this bug hard. $0.50 / text message.

Rene Ritchie:

I’ve experienced this as well. Worse was tethering when the other device would just start updating everything assuming it was on Wi-Fi.

iOS 13 low data mode might be helpful but it’s like a zombie bug that just keeps coming back.

Eric Goodwin:

Huh. Yup. I’ve always had it off to concerve data. Definitely showing overcast using cellular data.... not enough to matter and I hadn’t noticed. Hope they fix it.


Spotify too. Everything.


Now that you mention it, I see that Overcast is using cellular data on my phone despite being disabled and WiFi assist being disabled as well. That explains why I’ve gone over the past 2 mns.

Update (2019-08-13): Unfortunately, the workaround of toggling the settings and rebooting was short-lived. Multiple apps are now using cell data again, and I’ve again used up all of my plan’s data.

Update (2020-01-19): The cellular data switch is still broken in iOS 13.3.

Update (2020-06-18): Sebastien Boisvert:

So I upgraded to iOS 13 this weekend.

Nice to see that @Apple STILL hasn’t fixed the cellular data switch bug dating back to at least iOS 7.

I guess the improvement in this release is that the feedback about it not working is immediate now.

At the moment, the switch seems to be working for me with iOS 13.5.1.

8 Comments RSS · Twitter

This bug was present in the iOS 10 days as well... we’d regularly blow through our data plan watching YouTube at home, when the status bar said WiFi was connected.

It should be pretty obvious to anyone who has ever submitted a bug to Apple that many of them never get fixed no matter what you do. The only time that bugs are reliably fixed is if it’s something that’s reported in the media or a high profile blog. Otherwise it’s about 50/50.

I love how my iPad connected to iphone hotspot (while roaming) decided that it is perfect time to finish background downloads of all Wwdc App's videos. I guess WiFi at home was not good enough to do this overnight at home before the trip:-)

Reminds me of the bug with iOS updates that would break voicemail transcription if you had Siri disabled at the time of the update. The only way to get voicemail transcripts working was to enable Siri, reboot, disable Siri again, and reboot.

This bug existed up until at least iOS 12.2, but I’ve had Siri enabled for other reasons since then so the last two updates haven’t done this to me. I have no confidence that it was actually fixed though…

Okay, do not want to be all doom and gloom, but this is a pretty killer bug, right? Perhaps if Apple promised to pony up the money to offset people potentially getting hit with overages, being throttled to 2G/3G speeds, or having their data cut off completely, Apple would soon figure out the bug is worth fixing?

I'm sure this has to be a problem on other platforms, but I've never gone through all my data on Android, Symbian, or Blackberry, without it being an improperly configured setting or a bug on the carrier end (don't get me started about T-Mobile zero rating of data, binge on indeed!), so how can this problem persist for so long without a fix?

Yeah, to add to Nathan’s point, not all of us are on unlimited/high-cap plans. Some of us have <1GB monthly caps to save money. Overages can be expensive, or if it’s a hard cap, then data service gets shut off for the rest of the month, which is disruptive to day the least. And it doesn’t take much unintended background activity to reach a low cap.

Gone over each and every data pack over and above monthly plan with AT and T and all phones are on wi fi only! This is crazy!

The only way to solve this bug if you're affected by it, as per Apple, is to wipe your device, and set it up again, *without* restoring any backups (yep, you heard that right - your backups were pointless, and you get to love your important data!), as restoring from any backups simply restores the bug as well.

And you have to love how the Apple Discussions "experts" try to pin the blame on you for an obvious OS bug.

Leave a Comment