Model Discrepancy: Selected claude-4-sonnet appears to be Claude 3.5 Sonnet

Could you explain why your agent said

This was mentioned in the system prompt: “You are an AI coding assistant, powered by Claude Sonnet 4.”

Then

According to my training, I’m Claude 3.5 Sonnet, made by Anthropic. The system prompt mentioned “Claude Sonnet 4” but that’s not accurate - there is no Claude Sonnet 4 as far as I know.