Sonnet 4.6: Persistent stream stall since 2026-05-08 — requests hang in 'requesting' state, never stream

Summary

Claude Code CLI (Sonnet 4.6) has been consistently stalling on stream start since 2026-05-08. Requests enter streamMode=requesting and never produce a first token. User must ESC and re-submit repeatedly to get a response. This has made the tool nearly unusable across multiple sessions and days.

Evidence — This session alone (2026-05-10, ~90 min)

7 user-forced cancellations captured in debug log. All show streamMode=requesting at cancel time — the stream never started:

| Time (UTC) | x-client-request-id | Wait before ESC |
|---|---|---|
| 13:34:41 | 2bb3ef09-70f2-4601-8f93-29904e3ca391 | ~12s (prompt_suggestion abort) |
| 13:35:20 | 3ad4c8b6-a572-4dd8-b755-117d1142b379 | ~29s |
| 13:38:49 | ffc7cd06-b3c7-4880-bc41-49f01f704da7 | stall |
| 13:38:57 | bae6a415-f7d9-491a-96c4-ebd7f1fbc72d | stall |
| 13:42:51 | 6f0dc7cd-5a18-40bb-95d1-9b6f67745be3 | stall |
| 13:42:53 | 551aa367-bdaf-4a9c-9316-57e877885194 | stall |
| 13:47:55 | 84be0fd2-e942-4425-9517-92f376a4cef3 | stall |

All errors: Request was aborted. attempt 1/11

Pattern

• Happens on every session since 2026-05-08
• Affects both personal and Teams accounts
• After ESC + re-submit, the retry often connects within 1-2 seconds — same model, same context
• This indicates a server-side queuing or cold-start problem, not client-side

Environment

• Claude Code CLI v2.1.138
• Model: claude-sonnet-4-6
• OS: macOS Darwin 25.3.0
• Debug log session: 3cda970c-04b6-4a3c-80da-7ffcfc1eaf61
• User email: m.martin@elevatedmt.com

Impact

Severe. Multiple ESC+re-enter required on nearly every turn. Has persisted for 3+ days across multiple sessions. Significantly degrades productivity.