CoS can't assign via SMS

Hi Experts,

I currently met a very strange and complicated issue. I searched online but no one met the same issue as me. Hopefully, you can help.

I'm trying to update my current skilled worker visa for new employee. But my new employee can't assign me a new CoS as SMS shows that there's an UNUSED CoS for me. But I didn't accept any offer from other company. I have no idea where the UNUSED CoS come from.

I have contacted business helpline for help. They just advise the UNUSED CoS does exist. What can I do to get rid of the UNUSED CoS?

Kind regards,
May