The course fails when viewed from an iPhone, it takes me to the beginning

This happens when viewing the course from an iPhone (XR):

The course begins with a slide with audio and images that when finished automatically moves to the next slide, and instead of moving to the next slide returns to the beginning of the course.

I also tried to switch to the slide with a button instead of automatically but the error remains: the course starts from the beginning instead of advancing.

Making several publications, in one of them, the slide goes automatically to the next one, but pressing any button (with advanced actions) most of the time it fails and takes me back to the beginning of the course.

If anyone has any idea why this is happening on the iPhone I would appreciate your help. I've tried both Safari and Chrome. I publish in scalable HTML5.

Thank you very much.