"Parasitic cellular data drain" iPhone XS after iOS 18.x installed

[robbinia]

On July 7th I did a clean re-install of iOS 18.5 and then updated to the dev beta 3 of iOS 26 and since then the consumption of cell data has been really low. I started iOS 26 with none of my apps installed except My Data Manager and had nothing running for a few days then gradually reinstalled my apps and switched on location services, etc. It's used 192mb of cell data for system services since the update (avg 15mb/day) which is a massive drop compared to how it was on iOS 18.

For the past few days it's been back running as a 'normal' iphone & I'll definitely be updating to the public beta of 26 if/when it comes out this week as it seems way better running the new iOS (even in beta form) than 18.

 

[Newtons]

It’s bad enough all these tech companies make a lot of money from selling our data.

I hope they aren’t wasting our data somehow to spy on us, and then making us pay for the data consumption (minus the unlimited data plans)

 

[Neebee]

I can't believe the issue still isn't "recognized" by Apple. Just today I got hit with 120 MB+ drain after enabling cellular data. Sometimes, I can go for hours without the drain. The trigger seems to be whenever the iPhone "calls home". It sucks there's not much info online but I get it. Most people have insane amounts of data so it's not an issue. But if you're using a travel eSIM you need to pay more for a higher data bucket.

 

[Neebee]

On July 7th I did a clean re-install of iOS 18.5 and then updated to the dev beta 3 of iOS 26 and since then the consumption of cell data has been really low. I started iOS 26 with none of my apps installed except My Data Manager and had nothing running for a few days then gradually reinstalled my apps and switched on location services, etc. It's used 192mb of cell data for system services since the update (avg 15mb/day) which is a massive drop compared to how it was on iOS 18.

For the past few days it's been back running as a 'normal' iphone & I'll definitely be updating to the public beta of 26 if/when it comes out this week as it seems way better running the new iOS (even in beta form) than 18.

It's bizarre. My spouse's iPhone 13 has no issue and the settings aren't as conservative as mine. My XS can't upgrade to iOS 26. My guess is Apple doesn't care about us who have unsupported phones like the XS.

 

[ManuCH]

Honestly, you use a museum phone and you are on some plan from the 1980s. Maybe you should get an Android 😉