I suspect that the OpenRouter result originates from a quantized hosting provider. The difference compared to the direct API call from Moonshot is striking, almost like night and day. It creates a peculiar user and developer experience since OpenRouter enforces quantization restrictions only at the API level, rather than at the account settings level.
OpenRouter are proxying directly through to Moonshot - they're currently the only provider listed on https://openrouter.ai/moonshotai/kimi-k2-thinking/providers
That does include the Turbo endpoint, moonshotai/turbo. Add this to your prompt to only use the full-fat model:
-o provider '{ "only": ["moonshotai"] }'