When implementing aria on a set of tabs, I ran into a very unusual bug. It appears that when Voice Over is active and a tab is activated, focus is directed to an adjacent tab (rather than remaining on the activated tab) thus potentially causing confusion. I've put together an example with details about the bug and what I have found the cause to be. I've tested in Safari Tech Preview 9.1.1 (11601.6.17, 11602.1.33) and it appears to work correctly now, but I was unable to find a related issue. I thought I'd open an issue just in case. http://mfairchild365.github.io/aria-tabs-vo-bug/
<rdar://problem/26654328>
I should note that the bug can still be reproduced in WK Nightly r201711.
It appears that this might be caused by the presence of a hash fragment in the URL, which is used in my example. Another similar issue can be found here: https://github.com/ember-a11y/ember-a11y/issues/2#issuecomment-224357862
relating bug 163658