In Network ER, OON ER Physician

I went to the local ER after experiencing COVID symptoms and difficulty breathing on December 30th 2023. While there I got my vitals taken, a COVID test and a chest x-ray. The ER and the hospital in general are both in network, but the person who did my COVID test and ordered the x-ray to be done wasn’t. I didn’t know this, as the rest of the people involved were in network and I had paid all of the in network fees for the procedures, until months later when I got a text from a physician and staffing company saying that I had a bill for $800 dollars due for the OON physician’s services.

It turns out my insurance company had rejected the claim, which was billed as Emergency Department Physician Services – Level 4, a total of three times over three months on the grounds that the “Home Plan identified this claim is not a Surprise Bill, and a new SF is needed” until it appears they accepted it as a normal out of network bill and paid $110 out of the $930 bill.

Was this originally supposed to be a surprise bill? I thought that emergency services at in network facilities provided by out of network physicians was supoosed to abide by in network cost sharing policies? And if so, is there anything I can do now that it has been months since they approved it and paid a portion?