Screen jumping around on mobile

Can you have your users try in safe mode ? Does it also happen there?

What about meta, reproducible here?

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Issue persists with all three boxes checked

Reproducible on Meta, yes

If it’s worth anything is reportedly working without issue

idk if anybody on the team owns an iPhone 5s but that is thus far the only model of phone that has consistently encountered these issues that we’re aware of

Admittedly idt we’ve tried a 5

We do have browserstack so we can see if it reproduces there. I wonder if we are leaning on a JS API that is no longer available in old browsers.

This could be related to Discourse not loading on legacy browsers @david made this change, but @Falco mentioned we may also need globalThis?

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Assuming a fix is found, how long does it take to get pushed to stable? Given that’s what we’re on, and this bug makes the site basically unusable on mobile for a subset of our current users, I’m a bit scared at the idea of having to wait months for it - but we also can’t just swap off of stable, either.

Wait, so a backport to stable made it unusable on these browsers? Or stable was unusable ever since we cut it?

Not setting a deadline on this yet prior to having a good handle on the extent of the problem. As a general rule we don’t want to have broken behavior anywhere, however as browsers move out of our supported list they should fall back to HTML readonly view.

What is the exact version of browser the users are on? (exact iOS version should give us that info)

Stable should work fine on iOS 12 - it was cut before we started using replaceAll in the critical path, so the polyfill should not be required. The issue in the OP doesn’t look like it would be caused by a missing library.

More likely it’s a theme/plugin introducing the issue. @orangeandblack5 can you try in Safe Mode?

Also, any chance you can share a link to the forum?

(BTW I re-uploaded the video in the OP so there’s no need to visit wetransfer.)


Safe mode was already tried


Is there a particular topic which triggers this behaviour on Meta?


As far as I’m aware it’s global

Every (or at least most) topics experience this

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I don’t know how long this has been an issue, but I can ask

The user doesn’t know for sure when it broke because they barely ever use Discourse on mobile but they have memory of it working at points in the past - when asked “When would you say is the last time you are confident it worked on mobile?” they responded with “Around a year and a half ago” so realistically any changes to stable during that time could have been responsible - or perhaps before, if like ChiefDelphi we randomly happened to be working.

I definitely think that since Meta is known to not work it would be best to focus efforts here, and perhaps the owners of ChiefDelphi could be contacted to see if there are any particular differences that allow their site to work?

The one user has iOS version 12.5.5

I’ve asked the other user with an old iPhone 5s who confirmed the issue and will let you know when they respond

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Second user confirmed basically the same - iPhone 5s, 12.5.5, and yes it bugs out on Meta

So clearly whatever it is isn’t localized to our site or even stable

Which means it is well above my pay grade lol

I just merged this fix on tests-passed: FIX: Buggy topic scrolling on iOS 12 (#16422) · discourse/discourse@cd02ea0 · GitHub, it’s deployed here on meta. That commit fixes an issue where posts 20 and up wouldn’t auto-load and the topic progress counters (in bottom right corner of the screen) weren’t updating as the users scrolled the page.

The fix is small and will be backported to stable next week. Can you confirm here on meta whether it also fixes the issues raised in the OP? I don’t see an issue in an iOS 12.4 simulator, I don’t have an actual device on iOS 12 though.


Fix has been backported to stable, @orangeandblack5 please let us know if your users still experience issues on iOS12 even after a rebuild.


Will do, sorry I missed the last message.

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