[BUG] Voice dictation silently discards transcript on all platforms (web, macOS desktop, iOS) - long-standing, matches multiple closed issues

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

I'm hitting this consistently, and it appears to affect a cohort rather than everyone (otherwise this would be a much bigger, more visible issue for something this basic). Multiple closed issues describe the same bug: #55747, #55243, #59849, #55349, #38753, #44441 - all closed as duplicate/not-planned/stale, none with a confirmed fix. Filing fresh since the underlying bug is still very much alive.

Platforms affected: claude.ai web (Chrome and Safari, macOS), Claude macOS desktop app, Claude iOS app. Also filed as Anthropic support case 215474960906867, open 5+ weeks with one automated reply and no resolution.

Symptom: dictating produces nothing, a couple of words, or times out and discards everything.

Instrumented repro (web, done live with an AI agent watching devtools): recording captures audio fine - confirmed clean signal via getUserMedia + AnalyserNode level monitoring. Running webkitSpeechRecognition directly in the same tab transcribes perfectly (tested with a 20-count, zero errors), so the browser's own speech stack is healthy. Watching the composer during Claude's dictation, each newly recognized segment REPLACES the previous one instead of appending ("One" -> "Eight" -> "Twenty"), and when recording stops the composer is left completely empty. No transcription-related network requests are made during dictation, so it's a frontend rendering/state bug, not a backend or account issue.

Desktop app: waveform animates during recording (audio is captured), but confirming produces zero text - same silent-discard behavior as web.

iOS: fails differently, with an explicit error banner: "Sorry, we didn't catch that. Transcription failed. Please try again."

Timeline: dictation worked for about 1-2 weeks of daily use starting late May, then broke completely around June 5th and has stayed broken since (~9 weeks now).

Also possibly related, though a different failure signature: #72469 (Cowork desktop, mic activates then stops on 2nd attempt - no text at all, vs. the replace-then-discard behavior described above).

What Should Happen?

After stopping the microphone (or on transcription completion), the recognized text should be inserted into the composer, accumulating across the whole dictation, so it can be reviewed and edited before sending - not silently discarded or replaced word-by-word.

Error Messages/Logs

No error message appears on web/desktop (silent). On iOS: "Sorry, we didn't catch that. Transcription failed. Please try again." No transcription-related network requests observed during dictation on web (checked via devtools network panel), consistent with a client-side rendering/state bug.

Steps to Reproduce

1. Open claude.ai (or the desktop app / iOS app) and click into the message composer.
2. Click the mic/dictation button and start speaking a full sentence or longer (10+ seconds).
3. Observe: on web/desktop, each newly recognized word or phrase replaces the previous content in the composer instead of appending to it.
4. Stop the recording (click the confirm checkmark, or let it time out).
5. Observe: the composer is left empty - none of the dictated text is inserted. (On iOS: an explicit "Transcription failed" error appears instead.)

Verified this is not a hardware/mic/browser issue: audio capture confirmed clean via getUserMedia + AnalyserNode monitoring, and running the browser's native SpeechRecognition API directly in the same tab transcribes correctly with no errors.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Approximately early-mid June (worked for ~1-2 weeks before breaking)

Claude Code Version

N/A - not Claude Code CLI. Affects claude.ai web, Claude macOS desktop app (latest version), and Claude iOS app.

Platform

Other

Operating System

macOS

Terminal/Shell

Other

Additional Information

Reported to Anthropic support as case 215474960906867 (open 5+ weeks, one automated reply, no resolution). This may be tied to a feature flag or staged rollout affecting a specific cohort of accounts rather than everyone - I've asked support whether my account can be moved off it while the underlying bug is fixed. Happy to provide devtools recordings/console logs if useful.