issue with safari announcing legend associated with fieldset when voiceover is switched on. It was not read back to users. This is when users are navigating element by element, in context by performing a swipe gesture.
<rdar://problem/28214725>
It always occurs when user navigates in reverse order (swipe from right to left) and navigate into the radio group. On furthur investigation by the developer, it was found that it doesn't read correctly when the <form> is within a <main> element.
On further investigation we found that the legend is not narrated when the fieldset is placed inside a landmark roles with an exception from the form/region landmark roles.