Hi there,
I've reported this as a bug twice on bugs.limesurvey.org. Users on any Apple device (iPhone, iPad and Mac computer) cannot complete a survey because the Next button doesn't work a few questions into the survey. In my first bug report - bugs.limesurvey.org/view.php?id=16121 - I attached a screenshot and the message the participant is shown "Please use the survey navigation buttons or index. It appears you attempted to use the browser button to re-submit a page". Back then I was on version 3.22.11+200330. My more recent bug is bugs.limesurvey.org/view.php?id=16501 , this is with the latest version 4.3.3+200707.
This is extremely frustrating, and makes us look bad as an organization. We're sending surveys to 1000+ participants and those with iPhone, iPad or Mac devices can't get past the first few questions. I've had no action in response to the bugs, and if I can't get this resolved I'll be moving to SurveyMonkey or LimeSurvey Pro, but I'll have to be convinced my survey will work first!
Any suggestions appreciated.
Thanks,
Tom

Can you attach a small sample survey containing only the relevant questions?

Sure, I've attached the .lss file. It's not a long survey, though a number of the questions have conditions based on previous responses.
Thanks for quick response.
Tom

Please remove the link from your signature - that is only allowed for registered partners.

I see no attachment.

Let me try that again

This seems to be an environment problem - I can successfully complete the survey on my server (LimeSurvey version 4.3.4) using both iPhone and iPad.

Did you test with one of the core themes and/or on the demo site?

Is that something you could help me solve? I see that you have a survey consulting company, and I would be happy to pay to get this resolved.
The LimeSurvey build is 4.3.3+200707. database and DBv ersion MySQL 10.3.23-MariaDB-cll-lve, Server OS Linux, web server software & version Apache 2.4.43, PHP Version 5.6.40. Our domain is hosted on Islandhosting, and the LimeSurvey build is provided by them and installed using Installatron, we have a ComfortUpdate key. The survey theme is out-of-the-box "fruity". I will try the demo site, I've not used that before.

Actually, I was wrong on the PHP version, it's 7.4, and I've attached a screenshot of the activated and available extensions. . Do you see anything that points to an issue there?

Sorry, I am happy to help with front-end issues but am not a server expert.

Can you recommend anyone who might be able to help?

LimeSurvey build is 4.3.3+200707

1st think to do : use only 3.X version

Else : i really don't think iOs issue can come from server.
Last time i see such issue : it's due to a broken HTML : a div was not closed … in a question.
But strange Tony don't find the issue …