[BUG][A11y] macOS desktop: VoiceOver repeatedly re-announces the prompt/composer field during a turn (frequent re-renders)

Summary

On the latest macOS desktop app (version 1.20186.0), VoiceOver repeatedly re-announces the message composer / prompt input field (its placeholder / help text) while an assistant turn is in progress. Interim UI updates — status lines, streaming/intermediate responses, and tool-call progress — appear to trigger screen refreshes that VoiceOver interprets as changes to the composer, so it re-reads the prompt field over and over. This makes the app very difficult to use with a screen reader.

Environment

• Claude desktop app for macOS, version 1.20186.0
• macOS 26.5.2
• VoiceOver

What happens

• During a turn, as interim content is rendered (status/progress indicators, intermediate assistant output, tool output), the prompt/composer field's help text is spoken again by VoiceOver.
• This repeats frequently throughout a single turn, interrupting whatever the user is doing and making it hard to follow output or to type.

Impact

High for blind / low-vision users. The constant re-announcement of the composer competes with all other speech and effectively disrupts normal use of the app.

Suspected cause

A display artifact / unnecessary re-render of the composer — or a change to an element that VoiceOver treats as a live region or focus target — on each interim UI update. VoiceOver re-reads a field when its accessibility node is torn down and recreated, or when focus is moved back onto it, on every refresh. The frequency correlates with interim content being displayed during a turn.

Expected behavior

Interim / streaming UI updates within a turn should not cause VoiceOver to re-announce the prompt field. The composer's accessibility node and its focus should remain stable across re-renders.

Notes

• Reported by a fully-blind VoiceOver user. The exact trigger is not pinpointed because the interim status text is not fully spoken, but the correlation is clearly with interim content being displayed while a turn is in progress.
• Appears to be a recent regression — it became noticeable on the latest desktop build.

Related

• #71469 — [A11y] Add screen-reader (VoiceOver / NVDA) regression testing to the desktop app release process