I assumed it was more because the LLM might echo an understandable human claim of "if it's been unsolved for 370 years, it's unlikely to be solved now/likely to need expert knowledge", which is probably a mindset that appears in its training data.
The LLM likely needs to be reminded of its abilities.
> The LLM likely needs to be reminded of its abilities
Like when it tells you something is 3 days of work but it can do it with some degree of guidance in a couple hours