We have issues with pointer event and iPhones! Dam iPhones!
The cause of the problem is how the scroll is handled on the iPhone. Because depending on if you scroll up or down, the iPhone makes a bottom bar appear and disappear on your screen. And it can mess up with the pointer event, this one has offset which is randomly above or below the right position
An example: See the image below, the white sphere above the shirt is clickable, when the page finish loading it works good, if you play with the scroll going up and down, the sphere will not be clickable anymore. In fact, you will notice that the triggered has moved somewhere along the red line I have drawn.
Here is the link to the scene if you want to check it out: Owayn
As this is on mobile, I am not sure a playground is useful? Tell me if it can help.
@Deltakosh, I added pepjs