Codex Analytics shows GPT-5.4 for most turns, but my CLI is configured to GPT-5.5 — why?

I’m a ChatGPT Pro subscriber, and I’d like an explanation for an anomaly in my Codex usage statistics.

My setup • I use the service almost exclusively through the Codex CLI , rarely via the web UI. • My local config.toml explicitly sets the model to GPT-5.5. • I have never configured or manually selected GPT-5.4.

The problem On the analytics page (Settings → Analytics, chatgpt.com/codex/cloud/settings/analytics), under Usage → Turns → By model for the last 1 month (total 8,558 turns), the light-blue area (gpt-5.4) accounts for the overwhelming majority of my turns, while gpt-5.5 is only a thin band on top. The legend lists: gpt-5.4, gpt-5.5, gpt-5.4-mini, gpt-5.3-codex-spark. (Screenshot below.)

So despite GPT-5.5 being my configured model, most usage is attributed to GPT-5.4.

Questions (1) With my config explicitly set to GPT-5.5, why is GPT-5.4 used for the vast majority of turns? (2) Are requests being automatically routed / fell back to GPT-5.4? If so, what triggers it (capacity limits, task type, Pro-plan quota policy)? (3) Is this a reporting/display issue in Analytics, or is the actual model called different from my config? (4) How do I ensure requests always use my configured GPT-5.5?

Happy to share my exact config.toml model line and Codex CLI version if that helps with debugging. Thanks!