file NIW based 485, how to address job change?

I changed employer after approval of I-140NIW, but in similar field. Now the Employer only agree to verify my employment date, title, and salary, but refuse to describe my job in detail. What should I do? Can I say something in the 485 cover letter to describe my current job in detail and claim that it is still in the similar field and still benefit the national interest? Will this help to reduce the possibility of RFE?

thank you so much for any suggestion!!!