Hey, thanks for the report. This is expected behavior on the Free plan, not something broken on your side.
On the Free plan without your own API key, the model picker is locked to one model, right now that’s Cursor Grok 4.6 Medium, with a lock icon. That’s why it comes back after restart, and why unchecking models in Settings > Models doesn’t change anything. The lock overrides your selection.
Main point: the lock doesn’t disable AI. Cursor Grok 4.6 Medium works on Free within your included usage, so chat and agent are available. The Upgrade to Pro prompt is about unlocking other models, not this locked one. If you want to choose models like GPT 5.6 Sol, you’ll need a paid plan or to add your own API key in settings.
If you’re getting a specific error when sending a message, for example You’ve hit your usage limit, please share a screenshot with the exact error text and the Request ID (top right of the chat menu > Copy Request ID), and we’ll take a look at what’s happening on your account.
@nic_m, you’re on the Start plan, so it’s a bit different. If Composer shows an error, please send a separate screenshot with the exact error text and the Request ID, and we’ll dig in.
Related thread with more details on this behavior: Auto immediately switches back to Composer 2.5 Fast (locked) on Free Plan