[Bug] Context Truncation: Claude Sonnet Loses Context Prematurely

Bug Description
I note that inside the same coding chat (without compress chat neither clear chat) Claude Sonnet 4 forgets context somewhere in between 50% and 80% of the context size before it fills up (a rough approximation). I need to stop the chat and explain the correct context again because it likely forgets

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 1.0.120
• Feedback ID: 02836c70-57ad-4551-a31c-8e8f6cd3607a

Errors

[{"error":"Error: EISDIR: illegal operation on a directory, read\n    at Module.readFileSync (node:fs:440:20)\n    at Object.readFileSync (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:719:6848)\n    at x9B (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:3563:9983)\n    at Object.call (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1724:978)\n    at call.next (<anonymous>)\n    at VJ5 (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:3350:21057)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async WNB (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:3350:17339)\n    at async f9B (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1729:3422)\n    at async rJB (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1972:1631)","timestamp":"2025-09-20T06:10:03.696Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at iV (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:1184)\n    at file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:912\n    at Array.map (<anonymous>)\n    at TX (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:903)\n    at cNB (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:3368:13746)\n    at QC (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:84:19415)\n    at Jp (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:42814)\n    at W9 (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38355)\n    at Hh (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38283)\n    at zC (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38137)","timestamp":"2025-09-20T06:13:05.539Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at iV (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:1184)\n    at file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:912\n    at Array.map (<anonymous>)\n    at TX (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:903)\n    at cNB (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:3368:13746)\n    at QC (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:84:19415)\n    at Jp (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:42814)\n    at W9 (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38355)\n    at Hh (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38283)\n    at zC (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38137)","timestamp":"2025-09-20T06:13:05.553Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at iV (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:1184)\n    at file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:912\n    at Array.map (<anonymous>)\n    at TX (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:1794:903)\n    at cNB (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:3368:13746)\n    at QC (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:84:19415)\n    at Jp (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:42814)\n    at W9 (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38355)\n    at Hh (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38283)\n    at zC (file:///Users/leonardoleon/.npm-global/lib/node_modules/@anthropic-ai/claude-code/cli.js:86:38137)","timestamp":"2025-09-20T06:13:05.553Z"},{"

Note: Error logs were truncated.