Scroll Flickering Issue on iPhone

[Sowell]

Hi everyone,

I’m currently experiencing a serious display issue on my Shopify store since the iOS 26.0.1 update.
When I scroll up on an iPhone, the screen starts flickering rapidly, almost like a flashing or strobe effect, it’s quite intense and unpleasant for the eyes

This bug makes mobile navigation almost impossible.
I’ve already contacted the Kalles theme support, but their response time is quite long, so I’m hoping someone here might have faced a similar issue and found a fix.

Here’s what I’ve noticed:

• The issue only occurs on iOS 26.0.1.

• Everything works perfectly on previous iOS versions.

• Tested on several iPhones — same flickering issue on all devices running the new update.

• Tested on both Safari and Chrome mobile — same result.

For now, I’ve had to put my store in maintenance mode because of this, which is really frustrating.

If anyone has a solution, temporary fix, or any idea. I’d really appreciate your help!

Thanks in advance !

[PieLab]

Hi @Sowell

This is a classic rendering bug. Since you’ve confirmed it’s tied to a new iOS update, it’s a conflict between how Safari now handles rendering and a specific CSS rule in your Kalles theme, likely related to the sticky header.

While you wait for an official theme update, you can add a temporary CSS fix. This snippet forces iOS to use a more stable rendering method for the sticky element, which usually stops the flicker.

1. Go to Online Store > Themes and click Edit code on your theme.
2. In the Assets folder, open your main CSS file (likely theme.css, base.css, or kalles.css).
3. Paste the following code at the very bottom of the file:

/* Fix for iOS 26.0.1 scroll flickering bug */
.header-sticky, .sticky-header-wrap {
  -webkit-transform: translate3d(0, 0, 0);
  transform: translate3d(0, 0, 0);
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

After saving, clear any cache and test it on your iPhone. This should resolve the issue and allow you to take your store out of maintenance mode.

Hope this helps!

[Maximus3]

Not sure how you contacted them but The4 is always online if you go to their online chat within themeforest…

[SealSubs-Roan]

Hi @Sowell

That flicker is a known bug in iOS 26.0.1, and it affects themes that use CSS with sticky headers, scroll animations, or certain transform values. Disable position: sticky for now, or halt scroll-based animations in your theme as a workaround. Add something like this in your CSS:

• {
  backface-visibility: hidden;
  -webkit-transform: translateZ(0);
  }

It just makes for a smoother render and usually stops the flicker until they patch. When the next update for iOS is released, you can turn animations back on, with no ill effects.

[Sowell]

Hello, I sent a message on Friday morning (French time), but I had forgotten that they don’t work on weekends. I actually opened a support ticket, and they replied yesterday

[Sowell]

Thank you very much for your detailed explanation. I’ll try this solution and keep you updated. The theme’s development team is currently investigating the issue according to them, it’s related to the recent iOS update. They’ll let me know as soon as they’ve found a fix.

[Sowell]

The theme’s team is currently analyzing the issue. If they don’t find a solution in the next few days, I’ll apply your code and keep you updated. Thank you very much that’s really kind of you!

[Sowell]

I tested your code. I had some hope, because for a few moments it worked, but a few minutes later the bug suddenly came back ^^

Here’s the code for my store (100pablo60fury) if you want to take a closer look at the bug, in case you have the latest update