Mistral models never appear even though the API key is configured

I'm running Hermes WebUI self-hosted with Docker (via Coolify), together with hermes-agent.

I added my Mistral API key under Settings -> Providers, and the card says "API key configured". But Mistral models never show up anywhere. Not in the model picker in the composer, not in Settings -> Preferences -> Default Model, and not in the model dropdown when I create a new agent profile. All of those only ever list my Anthropic models.

A few things I checked:

• GET /api/models/live?provider=mistral returns 15 models, so the key clearly works and the WebUI can reach Mistral fine.
• GET /api/models returns active_provider: "anthropic" and only a single group (Anthropic, 10 models). There is no Mistral group at all.
• POST /api/settings with {"default_model_provider": "mistral", "default_model": "mistral-small-latest"} returns 200, but if I read the settings back they are still anthropic / claude-haiku-4-5-20251001. It doesn't return an error, it just doesn't stick.

Things I tried that made no difference:

• Updated from 0.51.92 to 0.52.106.
• Restarted both containers a few times.
• Added the key through the UI, under Settings -> Providers. That is where it shows up as "API key configured".
• Also passed MISTRAL_API_KEY into both containers as an environment variable, in case the agent only picks it up from the environment (it wasn't being passed through before). Neither route made any difference.

What I expected: once a Mistral key is configured, I can pick a Mistral model and set it as my default.

What happens: only Anthropic models are ever selectable.

Versions: hermes-webui 0.52.106, hermes-agent (image digest sha256:2f1f2f1725e5dc9a61cf6a2dea5aca52a776ec4d022cb29679e6aa3ff303e77a), Docker on Linux.

Is there some extra step needed to make the agent aware of a provider, or is this a bug?