Mistake on assigned COS

Hi All
I am an employer and recently issued a COS to a prospective employee (Chef 5434). His contracted working hours are 40 hours per week (£28080 per year salary). However, by mistake, I have put 42 hours on his COS. I also assigned the COS to him before the employee pointed out the mistake.

As I now cannot amend this, which is the best option?

1. treat as minor error and notify via SPONSOR NOTE

2. Withdraw COS and issue new one with correct details.

I know that cancelling the COS will affect my allocation, or can I request to reinstate due to mistake, cancellation, etc.?

I really appreciate your help. Thanks in advance.

Sponsor note is fine

Thank you CR001 for your response.