Version

4.12.1, npm

Describe the bug

• When navigating transcript, attachment uploads only reads “1 attachment” when on ‘activity focus’
• After pressing enter on the attachment, nothing is read aloud by AT
• Aria-hidden value is set on the anchor inside the attachment

Steps to reproduce

1. Open MockBot
2. type 'file', 'document-word', 'document-plain', and/or 'document-data-uri'
3. Chrome/NVDA:
   • When navigating transcript, attachment uploads only reads “1 attachment” when on ‘activity focus’
   • Enter to interact is not read
   • After pressing enter on the attachment, nothing is read aloud by AT
   • Also repros In mobile scan mode, bot activity is read twice before focus moves to an attachment #3804 behavior
   • Note: aria-live behavior works as expected
4. Edge/Narrator:
   • 'Enter to interact' is read as expected
   • Pressing enter on the attachment says "Nothing to interact" or something similar
   • aria-live behavior seems as expected

Expected behavior

When focus is on the attachment, "1 attachment, Press enter to interact" should be read.
When aria-selected is on the attachment, content of the anchor should be read

Additional context

[Bug]