HIV screening denied coverage

I recently went to a clinic for routing preventative screenings. Among the tests I had done was one for HIV. They coded it as 87806. I looked up the description for that on the web and found this:

87806 – Infectious agent antigen detection by immunoassay with direct optical (ie, visual) observation

It was a reactive flexible strip on which the nurse dropped a blood sample taken from a finger prick. Blue Cross denied the claim for this test. There were a few other tests performed, one of which was another blood test on a flexible strip. That one was covered in full.

When I asked BCBS about it, they responded with the following:

The claim in question processed correctly according to the information submitted and applied correctly towards your benefits. The code used on your claim 87806 is eligible for coverage, however subject to your benefit period deductible. It is not eligible for coverage under routine preventive care.

I’m confused why they denied it when it’s required by the ACA under preventative care. I confirmed that the clinic is in-network.

Do I just ask the clinic to recode and resubmit? Do I appeal with BCBS? It’s so frustrating that patients have to spend so much time dealing with this BS.

Thanks for the help.