Codex (VS Code extension) stops working mid-session with "model at capacity" errors

I’m consistently running into an issue using Codex in VS Code:

Setup:

• VS Code + Codex extension

• Model: GPT-5.4

• Mode: high

Problem: After ~3–5 minutes of normal work, the extension starts failing:

• “Selected model is at capacity” errors

• Requests stop going through

Question: Is this a known issue with the VS Code extension or model capacity handling? Any ETA on a fix or recommended best practices to avoid this?