Dentist is directly charging me the amount of my supposed in-network discount

Insurer is Anthem, I am also in contact with them directly and with my employer’s HR to try and get this worked out. I would just like to also find more about this if I can while I wait to hear back from them. The dentist is closed currently.

So my dentist billed $280 for a filling. My EOB from Anthem shaved $40 off of that for “in-network savings,” as the dentist is in-network, reducing the total to $240. My insurance then covered $100, leaving me with $140 remaining to pay. That’s all fine, but the thing is, my patient ledger for the dentist shows that they then charged me directly for an “insurance adjustment” that equaled the very same amount as the in-network discount, $40, bringing my balance back to $180 as if there was no in-network discount at all. Has anyone else experienced anything like this / does anyone have any advice that might help? I can look back at the ledger and see that they have upcharged me for “insurance adjustment” on previous visits also.

Thanks in advance