recent denials from BCBS for A-scans

I work in an ophthalmology practice where we do a ultraspund or "ascan" of the eye (procedure code 76511) prior to cataract surgery. BCBS has required us to breakdown the ascan into technical and professional components...these are now being denied as part of global billing for surgery. they used to always be paid w/o any problem. any thoughts?? thank you