Tabpanel reading difference between Chrome and Firefox
When trying the Orca behavior on https://www.w3.org/WAI/ARIA/apg/example-index/tabs/tabs-automatic.html because of the blank reading bug, I noticed that there's a difference in how the tabs are reported by Firefox 108 and Chromium 108. For example, try going using the down arrow to the first tab. On Chrome, only the tab is read, as would be expected. In Firefox, the key event is consumed and when Orca generates the speech for the next element, which is a child of the tab, specifically the section object of the tab, it uses the section specific unfocused speech format, so it grabs the ancestor presentation, which is the correct one of the tab, and then it adds the currentLine item for the section as well, so the title ends-up duplicated in the output. Note that layout mode was turned off for both browsers. This behavior happens with the latest revision from Orca master on F37.