Bug 264891

Overview:
Voiceover does not announce list aria-label, number of list items, individual item name and position in list when selected via arrow down/arrow up keys.

Steps to Reproduce:
Reproduced with official W3C examples of combobox autocomplete:
https://www.w3.org/WAI/ARIA/apg/patterns/combobox/examples/combobox-autocomplete-list/
https://www.w3.org/WAI/ARIA/apg/patterns/combobox/examples/combobox-autocomplete-both/

Open combobox list using mouse or keyboard and select any item using arrow down/arrow up keys
 

Actual Results:
1) For https://www.w3.org/WAI/ARIA/apg/patterns/combobox/examples/combobox-autocomplete-list/ example - only expanded state announced on open, list item information is not announced.
2) For https://www.w3.org/WAI/ARIA/apg/patterns/combobox/examples/combobox-autocomplete-both/ example - expanded state announced on open and then input element value changes after item selection via arrow keys, list item information is not announced.

Expected Results: When first list item selected, list aria-label should be announced, then total number of items in list, then item name and item position in list (e.g. 3 of 5). For subsequent item selections via arrow keys - item name and position in list. Such behavior implemented in NVDA and JAWS screen readers.

Build Date & Hardware: Safari 17.1 (19616.2.9.11.7) Mac OS Sonoma 14.1.1 (also reproduced on MacOS Ventura 13.6.1 with Safari 17.1)